COMPUTER TECHNOLOGYMinicomputers

JOSEPH B. SIDOWSKI, UNIVERSITY OFSOUTH FLORIDA, Tampa, Florida33620

The characteristics and costs ofminicomputers are discussed along withperipherals, time-sharing, and turnkeysystems. The article concludes with asurvey of over 100 small computersystems.

For the purpose of this paper, a surveywas made of binary computer systemswithbasic system costs of less than $30,000.Perhaps this is misleading as a pricedefinition of minicomputers, sincesomeofthe machines are expandable to such adegree that a fully instrumented systemwith maximum memory and attachedoptions can run well over $100,000. Somemanufacturers design their machines sothat the basic processor can be sold atminicomputer prices and then expandedmodularly into a system to meet mostneeds. So a more appropriate definitionmight have limited the basicsystemcost toabout $18,000 or less. The $30,000 limitwas exercised because it provides thereader with a broader comparative viewand incorporates. systems which arepresently in use in academic and researchfacilities. Opinions differ over what reallyconstitutes a minicomputer. An oft-quotedfigure is $25,000 or less. Other differencesrelate to capacityand function.

A 4,096-word memory can beconsidered a minicomputer basic, withmost memories expandable at extra cost to16k or 32k. Several are expandable to 65k,and a few basic processors are cited at l kor 2k (a few companies offer centralprocessors with no memory). Memorycycle times range from 775 nsec (onemachine lists .5/30 microsec) to8.0 microsec. Computer word lengths are8, 12, 16, 18, 20, and 24 bits, with the16-bit-word machines being the mostpopular. The 16-bit outnumber the8-bit-word computers by a factor of 3 or 4to 1~ The other word lengths make upabout 10% of the total.

Minicomputer central processors operatein a manner similar to that or the largercomputers--they are not, however,considered in the electronicdesk calculatorcategory, although the machines can fulfillmost of the functions. The processors aretypically fixed-point systems with singleaddress instructions which contain corememory, registers, an arithmetic unit, and

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I/O buses. Multiply/divide, read-onlymemory (ROM), special instructions, andother features are standard with somemachines, but optional with many others.A real-time clock is generally an additionalcost.

Although alike in many respects,minicomputers differ in regard to memorycycle and access times, input/outputmethods, interrupt systems, addressing,software, options, and so on. Perhaps themost common characteristics of the greatmajority of these machines, in addition tolow cost, is dedication to a particular task.Large-scale computers are often used for avariety of purposes and handle largeproblems; they cost more, generally,because of greater memory size, wordlengths, and attachments, such as disks,tapes, printers,and so on.

The potential buyer, of course, shouldknow what he wants out of the machineinterms of task performance(s), futuredemands or plans for system expansion,and how much he is willing to pay. Inlaboratories, the minicomputer hasfunctioned as a monitor, a controller, adata-acquisition unit, and as a data reducerand analyzer. If the buyer's interest ismerely to use the machine as an oversizecalculator or a mini number cruncher,he isbetter advised to travel another route. Thereal laboratory value of the small computeris .in its capacity for on-line real-timefunctioning. A realistic feel for thenecessary equipment and the costs ofon-line real-time laboratory computersystems can be obtained from the reportsby Haber (1968), Huesmann (1969),Mayzner (1968), Moise and Jarrard (1969),and Restle and Brown (1969). Of course,the machines can be connected to acommonmassdata base,e.g., a magtape ordisk. They can also be tied to largercomputers and to a common data base sothat the smaller machine can call forassistance when its capabilities are strained.In a data communication system, theminicomputer can be utilized as a terminaland as a preprocessor of data beforesending it on to a largercomputer.

Whatever the need, there are manycompanies to choose from. The number ofminicomputers on the market has increasedtremendously over the last 2-3 years. Newmanufacturers have appeared, older firmshave introduced new models or altered oldones, and middlemen have emerged whotake computers manufactured by others

and then develop and sell applied systems.At the same time, increased competitionand the introduction of new modularcomponents have sent the prices of minisdown so that less than $3,000 willpurchase a machine with 4k memory,8-bitword length, and a l-microsec cycle time.The newest addition to the DigitalEquipment Corporation (DEC) line, thePDP-8/E, is priced at $4,990 for the basicpackage and $6,500 with ASR-33teletypewriter. The DEC PDP-I,introduced in 1958, sold for approximately$120,000. Its more capable grandson, thePDP-8/L, was introduced 10 years later at$8,500.

Although prices are down, it isimportant to note that the basic unitsoffered by many manufacturers arestripped-down models offering littleflexibility. Some companies offer arelatively inexpensive basic package, butaccelerate the prices of optional, butnecessary, units. If a teletypewriter (thebasic minicomputerI/O device) is optional,the added cost may range from $800 to$2,000. Expanding the metnory of a basic$8,000 4k system, includingteletypewriter, to 8k could cost $6,000merely for the additional 4k. Yet 8k maybe needed for the use of FORTRAN,which the user may require. (Typically,memory costs represent about 50% of thetotal processor cost for minis.)Fortunately, as prices drop, it may bepossible to trade off between .programefficiency and memory size. As the pricesof additional memory units go down, thelanguages designed for on-line operationswillbe used more.

Technological trends are toward morecost-effective minicomputer processors andperipherals. The costs of bipolar and MOS(metal oxide semiconductors) digital logicelectronics are decreasing while speedsimprove. And thin film and semiconductormemories should challenge core memories.In projecting 106 -capacity memory trends,Zirnbel! cites core memory costs over thenext 5 years as 2¢-4¢/bit (0.25- tol-microsec cycle time), magnetic thin filmcosts at l¢-3¢/bit (0.10- to 0.5-microseccycle time), and semiconductor memoriesat ~d-2¢/bit (0.025- to 0.2-microsec cycletime). Plated wire memories providenondestructure readout, and stored datacan be modified easily. They alsoconsumelittle power or space. An all-MOS centralprocessor might have memory-centered

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logic, erasable and ROM stores, and morecomplex interrupt logic.

Industry projections made in 1969indicated an annual growth of 350/0-50% inthe minicomputer market. The most recentconcensus (September 1970) is that themark will be missed by a substantialamount. Some of the smaller firms arefinding sales outlets drying up, and a fewfirms have decided to postpone publicstock issues until market conditionsimprove.

Of cou rse, the most substantialminicomputer manufacturer has been theDigital Equipment Corporation. Thousandsof the DEC machines have been sold, andtheir service network is worldwide. Butother companies tum out very finemachines also, and their products warrantinvestigation. For the behavioral scientist,the DEC Users Society (DECUS) offers anadvantage because of the opportunity forinformation exchange between users ofsimilar machines; selected DECUSConference Proceedings are reported in theSeptember 1969 and March 1970 issuesofthis journal. Several other companies haverecently organized users' societies (e.g.,Data General Corporation and Varian DataMachines), which, in time, should grow andbecome more valuable. A number ofcompanies have substantial, tested softwareprogram libraries available.

Ollivier (1970) has developed a quickand effective technique for selecting smallcomputers that places heavy emphasis onevaluating the vendor as well as themachine. Both are rated on various factorswhich are weighted. Manufacturer criteriathat are evaluated include delivery time,past performance, number installed, andothers. Several of the computer criteria areword size, cycle time, addressing, andinterrupts. Prior to the evaluation,however, the task is analyzed, an envelopeof constraints is defined, minimumspecifications and maximum dollars areestablished, initial hardware/softwaretradeoffs are made, and a list of qualifiedvendors is developed for contact.

In comparing machines, it is importantto note that there is no standardization innomenclature and no restriction on the useof descriptive terms. The same type ofequipment supplied by variousmanufacturers may have different names.An input/output bus may be described as amultiplexer bus of some type, a party line,or something else. And the same name maybe applied to different items.

The remainder of this report will addressitself to a brief discussion of factorsinfluencing minicomputer operations, asomewhat cursory review of peripherals(the purchase of which often quadruple orquintuple the cost of the computer), some

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time sharing, and a survey of over 100small computer systems. Obviously, thisinformation is not new. Minicomputerhardware and software characteristics arecited in company brochures and reviewedin a number of technical publications.Many articles in this journal and elsewheredescribe computer-controlled laboratorysystems; Utall's volume (1968) providesinformation on real-time computertechniques in psychology. And the smallcomputer handbooks supplied bymanufacturers (e.g., Digital EquipmentCorpora t ion , Varian, Data General,Raytheon, and others provide a wealth ofinformation.

FACTORSINFLUENCINGMINICOMPUTER OPERATIONS

Several of the important factorsinfluencing minicomputer operations andcomparisons are listed below. As notedearlier, the most critical requirements arethat the computer perform the taskrequired at the necessary speeds, and thatthe price is right. Comparisons of hardwareand software capacities are important onlyinsofar as they satisfy the criticalrequirements. Routing data in and out ofthe machine is obviously important, and sois the capability of the peripheralsassociated with the job.

HardwareA core memorY"~r 4,096 words should

be considered minimum. For manylaboratory applications, and for the use ofsome software, at least 8,192 words arerequired. Obviously, if 4k will do the job,there is no need to pay for more memory.But in many on-line real-time experiments,researchers have gone to optional diskmemories and other means of increasingcapaci ty. The amount of memorynecessary to do the job should be evaluatedrealistically. It is not unusual to find a userstruggling to make a program fit thememory. One should also be certain toinquire as to which of the manufacturer'ssoftware will and will not operate with thebasic computer configuration.

An 8-bit-word module will cost less thana 12- or 16-bit-word module, but the 8-bitcomputer is not as powerful, although it issatisfactory if high performance andsophistication are not required. The longerwords allow more bits for data addressingand for instruction codes. However,evaluating or comparing machines strictlyon the basis of word length is difficult.

Memory cycle time is an importantcharacteristic as an indicator of speed, butit is the time that it takes the machine toexecute a program which indicates therelative speed of the machine in actual use.For some applications, Computer A with a

faster memory cycle time may have alonger run time than Computer B.

Memory parity checks and memoryprotection features are included in somemachines, but generally are optional. Paritycheck systems are used to facilitate errordetection. Memory protect requires thatspecial instructions be used to write incertain regions of memory; otherwise, theprotect prevents writing in that region.Lower- and upper-bound registersfrequently define the restricted core area.

Paging techniques are used by mostminicomputers to address core. The size ofthe page is determined by the number ofadjacent core locations that are specifiedby the address field. Although page sizesrange from 256 to 2,048 words, the mostcommon is 256. So the memory might bethought of as being divided into sections of256 words each.

Instruction sets and speeds must beconsidered also. For data and instructionsto be stored interchangeably in memory,data word length and instruction wordlength should be the same. Some 8-bitmachines use two words per instructions,operating like the 16-bit processors. Othersexpand instruction set by a byte-sharingtechnique-the instructions are divided intotwo acts, with one byte stored as part ofthe program. The other is stored as ashared byte and is referenced by the first.

A discussion of addressing is involved;suffice it to say, facilities are provided foraddressing the entire core. Generally,indirect addressing and indexing areprovided for addressing locations outsideof the page boundaries. Indirect memoryaddressing is a cross-reference techniqueand can refer to any level of addressingother than the first level of directaddressing; for example, an addressspecifies a storage location which containsanother address rather than the actual data.Indirect addressing provides greatflexibility, and some machines allowmultilevels of indirect. An index registeraugments addressing. Some computersprovide one, some, two or more, and a fewhave no registers of this type. Indexaddressing refers to an operation in which agiven address is added to the contents ofthe index register on command.

Reference to double-word-lengthinstructions means that the word is twicethe length (or width, if one prefers) of thenormal word. This increases the addressbits by an additional word length. If themachine length is 16 bits, a double-wordinstruction contains 32 bits.

Multiply/divide can be executed withhardware or carried out by softwareroutines. The hardware unit is optionalwith many machines, and the cost is high.On the other hand, execution is faster and

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the hardware units save memory spacebecause of the requirements made onmemory by the software subroutines.

The number of hardware registers andaccumulators provided in differentminicomputers varies. Additional unitsprovide programming efficiency, but alsoincrease costs. General-purpose registerscan be used as accumulators, as well as forindexing and other operations.

Read-only memories (ROM) arestandard with only a small number ofmachines. ROM speeds are much fasterthan the main core; the computers noted inthe survey range from 200 to 470 nsec.One function of the read-only memory isto store microprograms which are used toexecute microinstructions, an operationwhich requires that ROMbe faster than corememory. The memories are applied also toapplications in which one program isexecuted repeatedly. Some manufacturersuse ROM to protect and decrease real-timeprogram execution time.

In real-time operations, it is obvious thatinput/output (I/O) capabilities areimportant. One of the two basic types ofI/O channels transfers data under directcontrol of the processor program with thedata flowing through the registers. Thesecond type transfers data directly to thememory. A direct-memory-access channel(DMA) is generally optional. DMA permitsvery high-speed data transfer rates.

Of course, data transfers betweenexternal devices and the computer have tobe initiated. It is the interrupts thatcoordinate data flow in and out of thecomputer, an especially important functionin real-time operations. External interruptsare used under these conditions. Internalinterrupts usually deal with memoryparity, memory protect, power fail, andreal-time clock interrupt. Now interruptscan also be categorized as single or multiplelevel. The multilevel priority in terrupt isthe most sophisticated and is required formost real-time applications, although it isoften optional. Priority refers to the factthat the multiple levels, with devicesconnected to each level, are ranked so thata more important priority interrupt will beexecuted immediately, even if another levelis active. A real-time clock (optional fornearly all machines) is essential in thetiming functions associated with thereal-time operations.

For interacting with the computer,peripherals can be connected through anI/O bus, a direct-memory-access (DMA)channel, and a data channel. The I/O bus isstandard and is generally the main arterywith address lines, data paths, etc. The buscan handle more than one devicesimultaneously, but timing is crucial. Asnoted earlier, direct memory access (DMA)

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is not generally standard. The DMAchannel transfers data directly to and outof memory, an important feature whenextreme demands are placed on the centralprocessor by, e.g., special-purposeinstruments. The third method forinteracting with the computer, the datachannels, mayor may not be part of thebasic computer package. The primaryfunction of the data channel is to handleperipherals with relatively high datatransfer rates, e.g., disks and tape drives.

Multi plexer channels are generallyoptional and are used for time sharing.Optional general-purpose interface devicesare used for transferring data andcontrolling peripherals.

SoftwareA few years ago, there were complaints

con cerning software su pport forminicomputers, particularly the availabilityof compilers. That argument no longerholds, although only a minimum softwarepackage is provided with most basicminicomputer systems.

All manufacturers supply assemblers,loaders, and certain utilities as basic, andnearly all provide debugging. Some provideassemblers with macrocapabilities. Withhigher languages, macrocapability enablesan operator to execute these programs onother machines with a relatively smallamount of programming. Macroassemblershave other uses, of course; e.g., they areuseful when a series of instructions needsto be repeated.

Although out of style with largermachines, assemblers provide the primarylanguage for minicomputers. (An assemblercon verts easy-to-remember mnemonicsinto binary machine code.) One- andtwo-pass assemblers are generally cited asstandard. The two-pass is easier to use and athird pass helps with ASR-33 Teletypeinput and output. With a pass, theassembler scans the source program; thenumber of passes refers to how often theassembler does the scanning. Simulatorprograms are provided with manymachines, and these allow the programmerto debug his program on a larger machine.Separate debugging programs are especiallyvaluable since they allow the user to alterportions of the program. He should be ableto change the content of memory locationsthrough the teletypewriter, the printout ofcertain registers, and the display sectioncontents.

Compilers such as the FORTRAN IVmost often require 8k memories. (Acompiler translates English or mathexpressions into binary object programswhich may create subroutines of machineinstructions.) And one should be aware ofthe many varieties of FORTRAN; not all

have standard specifications. Basic andFocal are interactive languages availablewith minicomputers.

For real-time configurations, real-timeexecutive monitors are important, andthese usually require 8k core and, perhaps,disk storage. Some real-time operationshandle multiprogramming environments.But systems using foreground-backgroundprograms are expensive (the backgroundprogram handles batch jobs such ascompiling, and the foreground handles thereal-time program).

Finally, the minicomputer user is closerto his system than is the large-computerperson and requires detailed knowledge atthe machine level-experience that 'oftencomes hard and necessitates a great deal ofhands on practice.

This discussion of factors influencingminicomputer operations has been,admittedly, brief, and many variables ofimportance have been omitted. It does,however, provide descriptions of some ofthe important characteristics mentioned inthe computer system specifications.

PERIPHERALSPeripherals are units that are used in

conjunction, or in combination, with thecomputer. They are not, however,co nsidered an integral part of thecomputing machine itself. They dealmainly with input/output operations.Included in this category are I/O devices(card, tape, or printer units), terminals(typewriters, CRT, keyboards), drum anddisk memories, controllers and interfaces,and other miscellaneous devices.Instruments such as multiplexers and 0/Aand A/D converters are consideredperipherals by some computer people, butnot by others.

Virtually all minicomputermanufacturers offer a full line ofperipherals. But there is a growing numberof independent vendors who offercompatible units also. One can findnumerous supporters in the researchcommunity for purchasing either way. Aprimary reason for purchasing fromindependent vendors is cost; the buyerexpects a substantial saving for identicalunits. And he expects better performanceor additional features for his money. Onthe other hand, buying the computersystem from one source and the peripheralsfrom another may result in compatibilityproblems.

Several factors can influence the abilityof separate elements' to be connectedtogether and to function properly. Thereare, for example, hardwareincompatibilities. For example, are thecode and control logics compatible? Thetwo devices should interpret the same bit

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sequences in the same way, and they bothshould be parallel or serial. Are theelectrical characteristics, such as voltagelevels, rise and fall times, and loads,compatible? Is there a speed mismatch thatrequires buffering? Is there a problem inmatching the software? These are some ofthe problems which might requireconsideration. Fortunately, the number ofcom p anies marketing peripheralscompatible with specific minicomputersystem requirements is accelerating. Andthere are techniques for overcoming oraccommoda ting most mismatches."PI ug -to-plug compatibility" generallymeans that the unit is software- andhard ware-compatible and that theconnecting hardware is the same. So youmerely "plug it in."

Since the volume of data handled inminicomputer systems tends to be smallcompared to that of large machines, thespeeds of peripherals can be slower formany applications. And, as a result, manyperipheral units are relatively low in cost,e.g., disks, printers, cassette devices, somemag tapes, and other units. But even withthis advantage, the peripherals can cost asmuch or more than some minicomputingmachines.

The most common input/output, batchor conversational, terminal is theteletypewriter. Of these, the most widelyused is the Teletype ASR-33, which isoften offered as part of the basic systempackage. Model 33 is built for mediumwork loads; Model 35 is a heavy-dutymachine designed for high-volume work,but it has a higher price tag. The TeletypeCorporation ASR-33 operates at up to 10ASCII-8 characters/second, or 100bits/second in half- or full-duplex modes.Of course, the input of mostteletypewriters is the keyboard; paper-tapereaders are added to provide ASR(automatic send-receive) capability.

The IBM Selectric typewriter, whenproperly instrumented, might be used as aterminal also. Modular attachments may bepurchased which provide the Selectric withon-line terminal characteristics, yet do notdestroy the machine as an ordinarytypewriter. Information concerning suchunits may be obtained from the TerminalEquipment Co., 750 Hamburg Turnpike,Pompton Lakes, New Jersey 07442, orMicrodyne, 1600 South Hicks Road,Rolling Meadows, Illinois 60068.

If a keyboard and a CRT are combined,an alphanumeric and/or graphic displayterminal results which allows for thedisplay, receipt, and transmission of data.Hard copy of the received data can beobtained by photographing with a camera.Alphanumeric CRT terminals can be usedas stand-alone items or in multiterminalsystems. They are, however, expensive;

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single terminals can cost in theneighborhood of $10,000. Some of theminicomputer firms offer lower prices forCRT terminals incorporated into fairlylarge systems. But multiterminal systemshave a broad range of prices. A commonscreen size is about 7 x 9 in.

With term inals, there is also acommunication distance considerationbecause of signal deterioration possibilitiesat greater distances from the computer.The direct I/O cables of the Raytheon 706computer may have a length of 50 ft; thedirect-memory-access cables may have amaximum total length of 24 ft. DataGeneral cites data transmission distancesup to 50 ft (including internal wiring) asproviding good noise margins and lowsignal delays for the Nova and Supemova.But this problem can be handled byinterfacing components between thecomputer and external equipment.

The most efficient use of computer timecan be made with high-speed I/Operipherals. A number of minicomputermanufacturers offer (generally as options)various punched tape, punched card,magnetic tape, printer, plotter, and otherconfigurations. Punched tape, .with itsserial organization, is considered in theslow category of the high-speed I/Odevices, but it is relatively low in cost.Magnetic tape units are much faster andhave greater capacity, but the cost isgenerally higher.

The methods for reading punched tapeare mechanical (holes are detected bymechanical means of some sort, such assensors) or photoelectric. The latter canread up to 1,000 characters/second.Although mechanical readers are slower,they are also less expensive. The Model 33and Model 35 Teletype units providehardcopy output at 10 characters/secondat 72 characters/line. On eight-level tape,the paper-tape punch and reader operate at10 characters/second. Other paper punchesare available which operate at 60 to 1IOcharacters/second. Eight-channel ASCII isthe most common punched-tape code. Ofcourse, there are paper-tape readersavailable operating at upwards of 300characters/second. (Because of high costs,card punches and card readers are seldomused with minicomputers. This is not todeny the fact that some laboratory oreducational systems require andincorporate them.)

Most magnetic tape units forminicomputer use are advertised asIBM-eompatible, but care should be takenin verifying the claim. The tapes for thesemachines have seven or nine tracks withpacking densities of 200, 556, or 800bits/inch. Conventional tape drives may beused, but incremental drives are lessexpensive. Incremental drives are similar to

conventional computer mag tape drives,but data blocks are written one at a timeinstead of continuously. Also, data transferrate is much slower, e.g., several hundredcharacters/second compared to severalthousand characters/second. Faster speedsare often available as options. For example,the Kennedy Company (540 WestWoodbury Road, Altadena, California91001) Model 1600 incremental recordercan operate at speeds of 0-300characters/second, with speeds of 0-750and 1,500 characters/second available asoptions.

Cassette and cartridge digital tape unitsare rapidly gaining in popularity, althoughat this writing they are offered by arelatively small number of computermanufacturers. Units are available withminicomputer interfaces from severalperipheral manufacturers. Cassette andcartridge recorders should be pricedcompetitively with paper-tape transportsand, in general, offer the advantages ofincremental mag tape units. But computertape compatibility is a problem. Atpresent, few appear to be interchangeable.

As data storage devices, cores, drums,disks, and tapes may function in support ofthe computer memory. They may also havedata-handling tasks in the peripheralconfigurations. Disk storage units can beobtained from just about all minicomputermanufacturers as well as from severalperipheral vendors who supply interfacesfor most small computer machines.Fixed-head, nonremovable disks arepopular. (An 18-microsec access time, with32,000-word capacity and100,00D-word/second transfer rate mightdescribe a typical unit.) In purchasing, it iswise to compare access times and transferrates, especially in regard to the recordlength being read out at each accessing.

A mass storage system which is neitherdisk nor drum is the DA-060 magnetic tapesystem for small computers. The unit has a4-m illion -word capacity, bidirectionalrandom access, and a 16.6-kC word rate. Itis compatible with the DEC PDP-8machines. The manufacturer is SystemsIndustries, Inc., 535 Del Rey Avenue,Sunnyvale, California 94086.

There are, of course, many otherperipheral devices that have not beenmentioned in this section. But moredetailed descriptions and explanations offunction are best left to other sources.

Several peripherals are listed below.These are merely representative of a largenumber of peripherals in numerouscategories and indicate no preference forany single unit listed or otherwise.Computer manufacturers market similardevices.Printers

The Nortec 200 is a 132-eolumn

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ControllerThe Progress Electronics Me-16 Multiple

Device Controller is an off-the-shelfinterface between the MAC-16 computerand devices normally used in smallcomputer systems for real-time control ofmultiple parallel-data peripherals. The datatransfer rates are up to 200,000 l e-bitwords/second, with selection of up to 16addressable devices. The instrumentfeatures control of one 60<hannelanalog/digital converter system under onedevice address, con trol for eightaddressable digital/analog converters, 16con trol lines expandable to 128, 16 senseJines expandable to 128, and four codedinterrupt lines organized under oneinterrupt level. The price with D/A GeneralData Channel and Multiplex A/D Control is$910 (progress Electronics, 5160 NorthLagoon Avenue, Portland, Oregon 97217).

Memory Drum ControllerDatum, Inc., markets memory drum

controller systems for HP-2114, -2115, and-2116 computers. The system contains adrum memory, a controller, and allnecessary connecting cables. Depending onthe model, storage capacity (l6-bit words)ranges from 32,768 to 262,000. Up to fourdrums can be controlled. The price of onedrum memory with connectors (32,76816-bit-word storage) is $5,800; drummemory with 262,000-word storage is$11,500. Transfer rates of 88,000,120,000, or 130,000 words/second aredependent on the drum selected. Softwareis compatible with HP (Datum, Inc.,Peripheral Equipment Division, 170 EastLiberty Avenue, Anaheim, California92801).

Disk MemoryComputer Systems and Software, Inc., is

marketing two disk memories, one for theNova and one for the PDP-8 systems. TheNova-compatible memory has storagecapacity of 250k 8-bit characters and atransfer rate of 62.5k words/second. ThePDP-8-eompatible system has 512k 6-bitcharacter capacity and 128k words/secondtransfer rate. Access time is 8.4 msec forboth systems. Price: $9,000 (ComputerSystems and Software, Inc., 811 NorthMagnolia Avenue, Orlando, Florida32803).

Information Data Systems has a diskmemory system with a capacityapproaching 145k bits of storage. Thesystem has eight data tracks, each with acapacity of 18,125 bits. Access time is8.5 msec. Price: $1,812 (Information DataSystems, 8620 East Eight Mile Road,Detroit, Michigan 48234).

Cassette SystemA cassette tape-transport system, the

Compu/corder 100, enables minicomputersto access any tape file within an averagetime of IS sec. The system comes completewith software and interface to DEC,Varian, and Data General computers.Standard features include read/write speedsof 5 in./second. Typical tape may contain3.6 million bits. Recording density is1,000 bpi; a bit-serial, biphase-encodedwidefield recording technique provides atransfer rate of 5,000 bpi. Each cassettehas 300 ft of computer-grade tapepreformatted with address track. Price:$2,950 (Sykes Datatronics, Inc., 375

Model 2914 Daconics mag tape Orchard Street, Rochester, New Yorksubsystems sell at a ballpark price of 14606).$1 1,500. The equipment includes aPeripheral Equipment Corporation 6840-9tape unit, connecting cables, Daconic'sinterface and controller 2914-1, andsoftware. Packing density for the ninechannels is 800 bpi and the tape speed isup to 37.5 ips. Data transfer rate is up to30,000 bytes/second. Models are equippedfor interfacing with Hewlett-PackardComputers HP-2114 A/B, 2115A, and2116B, and the DEC PDP-8 and -9(Daconics, 50S West Olive Avenue,Sunnyvale, California 94086).

The Infotec mag tape system iscompatible with and designed for thePDP-8 series processor. With read/writespeeds of 25 ips, the TS-8C mag tapesystem has data transfer rates of 20kcharacters/second. Direct memory access ispossible. Data density for the nine-trackconfiguration is 800 bpi; for seven-track,200/556 or 556/800 bpi. Tape velocity of5.0 ips is standard. Data transfer rate is4k Hz at 800 bpi. Price: $11,300 (Infotec,Inc., 70 Newton Road, Plainview, NewYork 11803).

Digital Scientific Corporation (11455Sorrento Valley Road, San Diego,California 92121) manufactures a magnetictape controller compatible with the DECPDP-8 computers, the Honeywell DDPfamily, the Varian 620i and 520i, Interdata2, 3, and 4, and HP-2114, -2115, and-2116.

The CO-600 LINC tape system providesa randomly addressable mass-storage devicewith dual tape drive and controller.Capacity of each tape is 204,800 bytes.Data transfer rate is 8,400 bytes/second.The system uses phase recording,400 bits/inch in density. On-line storagecan be increased to 3.2 million bytes.Interfaces are available for the Varian 620series computers, the Honeywell 315 and516 machines, the HP-2114, -2115, and-2116, and the General AutomationSPC-12 (Computer Operations, Inc., 10774Tucker Street, Beltsville, Maryland 20705).

machine for minicomputers that prints at200 lines/minute and is slightly larger thanan electric typewriter. It is not a drumunit. The printer is IBM-eompatible andaccepts ASCII-eoded alphanumeric 6-bitdata at rates up to 500 kHz. Price: Over$6,000 for single units (Nortec ComputerDevices, Inc., Ashland, Massachusetts01721).

The Di/An Pony Printer mates directlywith a number of minicomputers and ispriced at approximately $9,900. Printingspeed is 1,280 characters/second fornumeric and 640 characters/second foralphanumeric. The 32-eolumn machineprints 2,400 lines/minute for numeric andI ,200 lines/minute for alphanumeric(Di/An Controls, Inc., 944 DorchesterAvenue, Boston, Massachusetts 02155).

The Data Products miniprinter costsover $6,000 for single units and has a drumspeed of 1,760 rpm, 80 columns, andlistings as fast as 111 lines/minute for 20columns (Data Products Corporation, 6219De Soto Avenue, Woodland Hills,California 91364).

The Eclectic Model 740 printer systemallows a 136-character line width to beprinted in 8 in. or less. The machine printsat 250 characters/second and is priced at$7,500 (Eclectic Computer Corporation,Suite 301, 3707 Rawlins, Dallas, Texas75219).Magnetic Tape Systems

Datum, Inc., markets magnetic tapesystems with software for virtually allminicomputers. The system isIBM-eompatible, with data densities of800 bpi for nine-track and 800/556,800/200 for seven-track.

The ECC 640 mag tape system forPDP-8 computers reads and writes seven- ornine-track 200-, 556-, or 800-bpi records.Standard tape speed is 24 ips. Data istransferred at 10k 12-bit words/second.The system is priced from $10,400.(Eclectic Computer Corporation, Suite 301,3707 Rawlins, Dallas, Texas 75219).

Over 25 minicomputer interfaces areavailable for CartriFile, an EDP systemwith four mag tape transports, cartridgeloaded, starting at $2,900. (TRI-DATA,800 Maude Avenue, Mt. View, California94040).

The Computer Equipment Corporationmag tape system is IBM-eompatible, withcontroller, interface, and software forPDP-8 computers. The system consists of aCEC Model 640 controller interface and anAmpex Model TMZ tape transport. Withseven-track, read and write is 800 bpi. Anine-track system is available. Computeraccess transfer rate is 10k 12-bitwords/second at tape speeds of24 in./second. Price: $8,200 (ComputerEquipment Corporation, Suite 214, 3707Rawlins, Dallas, Texas 75219).

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

Disk ControllerInformation Data Systems 5000 Disk

Controller is designed for the Interdata 3and the Data General Nova computers. Thecontroller for Interdata 3 can handle up to256k 8-bit words, expandable inincrements of 32k to eight times thatamount. The unit can also handle rates upto 1.2 million bits/second. The Nova unitcan handle up to 128k of 16-bit words.Prices start at $3,580 (Information DataSystems, 8260 Eight Mile Road, Detroit,Michigan 48224).

Disk-Drive InterfaceBedford Associates, Inc., market an

interface for the control of as many aseight Memorex 630 or 660 disk drives bythe PDP-8 family of computers. Price:$13,500. An optional automatic 630-660select permits any mix of Memorex 630 or660 disk drives to be controlled byinterface (Bedford Associates, Inc., P.O.Box 327, Bedford, Massachusetts 01730).

InterfaceThe Fabri-Tek Signal Averager and

Processor provides interface boards to thePDP-8 for $1,500, the PDP-8/I or PDP-8/Lfor $1,000, the PDP-9 for $2,000, thePDP-12 for $1,000, and the PDP-15 for$1,500 (Fabri-Tek, Inc., 5225 VeronaRoad, Madison, Wisconsin 53711).

Software PackageDigiscan Services, Inc. (425 Broad

Hollow Road, Melville, New York 11746)markets a software package which allowsalmost any minicomputer to act as aremote batch terminal and to communicatewith a central IBM-360 computer overtelephone lines. Residing in the computer,the software simulates 360communications hardware, so theprogram mer can use th e BTAMconventions governing 360-360transmission. The software controls theentire transmission sequence. Price:$10,000.

Audio Response SystemsMARS (multiplexed audio response

system) is a free-standing system forinformation retrieval by means of anelectronic voice output. MARS is equippedwith computer and dataset interfacecircuitry and is multiplexed to allowcomputer output of many voice responsesover lines simultaneously. The multiplexingcapability is modular and can be increasedas demand grows. Vocabularies arcavailable in 31, 62, 93, or 189 words.Inquiries are initiated by the user'stelephoning the computer by usingTouch-Tone phone, rotary dial phone withTouch-Tone adapter, or inexpensive

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remote terminals. The system providesautomatic answering of incoming calls andvoice response to the inquiries.

MARS interfaces with the PDP-8 familyof computers, their available peripherals,and with Dataset. Special configurationsare available, compatible with otherminicomputers. Query time is 0.3 sec/fourlines. Processor time depends on theassociated computer-typically 0.1 to0.5 sec. Number of words in response:0.53 sec/word plus 0.26-sec average accessto first word.

MARS consists of a Cognitronicsmultiplex SPEECHMAKER system withpower supply and interfacing circuitry.Price of the MARS system alone is $17,820to $24,660, depending on the size ofvocabulary and the number of lines(SPEECHMAKER, Division ofCognitronics Corporation, 333 NorthBedford Road, Mt. Kisco, New York10549).

TIME SHARINGWith time sharing, numerous terminal

devices can utilize a computer concurrentlyfor input, processing, and output. Severalindividual users, or one user with a numberof experimental stations or inputs, canshare the machine for different purposes atthe same time. The speed of the computer,of course, makes it appear that they are allsharing simultaneously. Actually, themachine is handling each in sequence.

A large number of time-sharing systemsare available. Three are briefly noted here.Two others, the Wang and Mini-Compsystems are mentioned later in thecomputer review section, as are individualdescriptions of the DEC, Hewlett-Packard,and Data General computing machines.

Digital Equipment CorporationOne of the systems marketed by Digital

Equipment Corporation, Timeshared-8, iscapable of running up to 32 differentterminals simultaneously. The system startsat four users and is expanded by addingmemory and mass storage devices: 32,000words of core memory, four 250,000-worddisks, eight DECtape units, and expandedsystem software. Organized around thePDP-8/I computer, the Timeshared-8 canbe interfaced to a larger time-sharingmachine like Digital's PDP-I0.

The basic eight-user system with PDP-8/Icomputer has 8,000 words of corememory, 250,000 words of disk storage, ahigh-speed reader, and time-sharinghardware and interface equipment forabout $45,000. With 16,000 words of corememory, 500,000 words of disk storage, ahigh-speed reader and punch, and necessaryinterface equipment, the cost increases to$65,000. A 36-month service contract for

this expanded system is an additional$9,000, bringing the total price to$74,000. The expanded 16-user system has20,000 words of core memory, one millionwords of disk storage, high-speed readerand punch, four DECtapes and control,card reader, PDP-lO interface, data phoneinterface, and time-sharing hardware andinterface equipment for approximately$110,000.

Hewlett-PackardHewlett-Packard offers the HP-2000B

system with a capability of 32 terminals orusers. The HP-2000B is an extension of theHP-2000A 16-terminal computer system.

This new system provides Basiclanguageprocessing for the 32 terminals ata 30%increase in price. The 2000B costs about$120,000, as opposed to about $91,000for the 2000A, and is built around theHP-2116 B computer, a 16-bit machinewith a 16k memory and l.6-microsecmemory cycle time. In the 2000Bconfiguration, a second computer handlesthe HP-2114B with a 8k core memory;additional storage may be added. Anyterminals can be wired directly to thesystem if it is located within a l-mile radiusof them. Telephone communications areused for greater distances. Terminals in thesystem are ASR-33 or -35 Teletypes. Thestandard configuration with an ASRTeletype and 12-megabits of mass storagecan be leased at $3,117 per month.Deliveriesbegan in late 1970.

Data GeneralThe Data General Nova 4-user system

costs $5,585 per terminal for a $22,340total. The Nova provides 2,728 8-bit bytesof core storage per terminal, 16-bit wordlength, and multiaccumulators.

A 16-user Supernova system is priced atabout $3,142.69 per terminal, or a total of$50,283. The Supernova provides 1,4968-bit bytes of core storage, 16-bit wordlength, multiaccumulator, and an 80Q..nseccycle time. Basic time-sharing language isused with full extensions. For stand-aloneuse, software includes: FORTRAN IV,ALGOL 60, a disk operating system, andothers.

TURNKEY SYSTEMSLehigh Valley Electronics, Inc., and

Grason-Stadler have developedcomputer /interface installations for thebehavioral scientist which are essentially"turnkey" systems for on-line real-timeresearch or teaching applications. Both willprovide programmed, installed systemsready for the buyer to sit down and startflipping switches. The customer candescribe what he wants to control andwhat the control parameters will be, and

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

the company will try to do the rest bysetting up the computer/interface system,install peripherals, provide the software,debug the system, set it up ready to go,and provide instructions on how to operateit. This, of course, is the "custom made"extreme, both in demands and in price.Either company will also providehardware-interface/software packages tothe buyer who has his own computer orprefers to buy a machine independently.

At the present time, the Lehigh ValleyACT language is written for the DECPDP-8 series and for the Data General Nova4,096-word machines; however, theINTERACT system can be adjusted forother computers in the same category. TheGrason-Stadler SCAT system is designedspecifically for the DEC PDP-8, PDP-8i,and PDP-I2 computers with extendedarithmetics. As of this date, several SCATsystems are in operation in psychologicallaboratories, including installations atFlorida State University, the University ofTexas at Austin, and the WisconsinRegional Primate Research Center.INTERACT is a new system which is nowbeing installed under contract with severalbuyers. .

Both INTERACT and SCAT attempt todeal with a problem of primary concern inon-line real-time multiple-stationtime-shared behavioral research efforts,namely, interface and software.

The total INTERACT system consistsessentially of the ACT language, theinterface hardware INTERACT, an ASR-33teleprinter, and the computer. LehighValley Electronics's behavioral testequipment, animal or human, is optional.The software segment is ACT (AutomaticContingency Translater), a general languagefor on-line control of psychologicalexperimentation developed by J. R.Millenson, which enables the user to writeprograms in English. The INTERACTcontrol has a built-in time generator whichgenerates unit time pulses to measure allactions; it also has a random-numbergen era tor. Eleven stimulus/responseoutputs are offered per station. Thecontrol panel is equipped with driverpackages so that the outputs can be tieddirectly to feeders, stimulus lights, buzzers,etc., although no special driver packagesare required for many standard devices. Aswith most computerized time-sharingsystems, the number of stations is definedby the size of the memory, roughly onestation per Ik of core memory. So a 4kmachine could control four stations,possibly more, depending on thecomplexity of the program. '

The Grason-Stadler SCAT language, anacronym for State Change AlgorithmTerminology, is constructed around the

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

basic concept of STATE (Stadler, 1969).STATE is characterized by two primaryattributes: the initiation of a set ofphysical events (e.g., stimuli that can becontrolled by interface hardware, controlconditions such as D/A conversions, etc.),and the continuance of the set of eventsuntil a condition has been met, at whichtime transition is made to a new state (e.g.,a time interval completion, the terminationof a 0/A conversion, etc.). The interfacepackage provides provisions for: acceptingbinary information on three input linesfrom each station and for combiningunusual input lines for communicationwith any single station, issuing controlinformation to eight output devices in eachstation, timing operations, and necessarysignal shapers, logic, etc.

Prices of the INTERFACE system with a4k memory NOVA computer and fourstations is $29,995; with 8k and eightst ations the price is $39,995. Theinterface/software package, less DEC orNOVA computer and Teletype, is installedfor $19,795 with four stations and for$25,795 with eight stations, less NOVA.

SCAT costs $40,750 for the basicpackage with the PDP-8 series computer(with extended arithmetic, PTO, andASR-33) and five stations. SCAT alone,with your computer, is priced at about$20 ,000. An additional five-stationexpansion costs $10,600.

MAINTENANCEA computer buyer should assess and

make provisions for maintenance needs.Some estimates cite the price ofminicomputer maintenance per annum atabout 6'1<>-8% of the system's purchaseprice.

Now there are several things that onemight do. A potential purchaser mightinvestigate failure and reliability statisticscovering the computer, and check withindividuals who use the machine,preferably more than one or two. Sincefield maintenance capabilities areimportant, the location of the servicerepresentatives warrants consideration, asdoes reputation for service, and therepairman's response time. Field engineersuntrained or inexperienced in maintainingperipheral equipment might also present aproblem, unless computer and peripheralsare purchased from different vendors. Butthen, if the system becomes inoperative,must two service calls be made? And, ifone serviceman is called, will he pass thebuck to the other?

Another consideration, after the initialwarranty period, is whether to assume themore general maintenance responsibilitiesyourself, have another laboratory persontrained for the job, or hire an experiencedminicomputer technician. Finally, there is

the possibility of contracting formaintenance with a local organization withexperience on similar machines. If so, feesmay be negotiable.

In any case, warranties needexamination for coverage of parts andlabor, and the length of such services. It isprobably wise to negotiate themaintenance agreement and warranty as apackage a t the time of hardwareacquisition. It is then that the buyer hassome leverage.

MINICOMPUTER SURVEYThe computer systems are listed

alphabetically according to company name.As noted earlier, the basic minicomputerprice is defined here as below $30,000;expanded systems, of course, can costmuch more. Time-sharing systems generallyexceed this limit, but the controlcomputing machines fall within the scale.A few higher-cost machines are citedmerely for comparison with the samecompany's minicomputer product. Finally,the reader should be alert to the fact that acomputer firm will occasionally changeprices or specs from one announcement tothe next. Fortunately these are most oftenin the form of lower costs and fasteroperating speeds resulting from marketdemands and competition.

Applied Systems Corporation18325 West McNicholsDetroit, Michigan 48219

ASC·II00The ASC-lIOO system is designed to

operate as either an independent,self-contained computer system or tocommunicate optionally with larger centralcomputer facilities over communicationnetworks. The central processing unitincludes a magnetic core memoryexpandable to 32 kbytes in 4k modules. Abasic memory configuration of 1,024 bytesis also available. Byte length is 8, 9, or 10bits. Core memory speed is 1.1 microsecfull cycle.

The processor also incorporatesread-only memory with a 22Q.nsec cycletime. Optional capacities range from 256to 1,024 words of 16-bit length.

The ASC-llOO can be programmed ateither the micro- or macroinstruction level.At the macro level there are 89 standardinstructions. Instruction format is variable,from 8 to 32 bits, dependent uponoperation and addressing mode. At themicroprogramming level, a set of 26 typesof commands are provided, using threebasic command formats. Each command is16 bits in length and execution time is220 nsec. Software includes FORTRAN

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and an assembler. The CommunicationsSupport packages provide softwarenecessary for using the system as a remoteterminal. Normal communicationtransmission rates are employed from2,000 baud to 4,800 baud, full or halfduplex, with EBCDIC or USASCII.

Price of the system depends on theconfiguration. The basic model is $5,950but includes only the computer processorwith 256-word read-only storage, areal-time clock, and control console.Additional 256-word modules of read-onlystorage cost $750. A 1,024-byte moduleof magnetic core memory is $1,500; a4,096 module is $2,850. So a reasonablesystem will range upwards from $12,000.

Atron Corporation1256 Trapp RoadSt. Paul,Minnesota 55118

AtronThe Atron was originally designed for

data handling and business processing. Thebasic processor offers three-address binaryand decimal arithmetic, instruction setconsisting almost entirely of macros, andvariable-length words of up to 256 8-bitbytes. The memory has a 2-microsec cycletime for an 8-bit byte and is expandablefrom 4k to 32k bytes. The basic computercosts about $7,500 in single quantities. Asystem with 4k of memory, a400-card/minute reader, a 300-line/minuteprinter, and half-duplex communicationscapability would cost about $37,000.

Beckman Instruments, Inc.2500 Harbor BoulevardFullerton, California 92634

Beckman Model 816The Model 816 is a 16-bit-word-lcngth

computer with a 4.8-microsec memorycycle time. Minimum memory sizeis 2,048words; maximum is 4,096. The machinehas 16 hardware instructions, one hardwareindex register, and two accumulators.Input-output data path is 16 bits at amaximum word transfer rate of 6 kHz. Afull line of peripherals is available, as is anextensive software library. Rack height is12.25 in. Basic unit price is $8,800 with2,048 words of memory. With ASR-33 and4,096 words, the cost is approximately$13,000.

Business Information Technology,Inc.5 Strathmore RoadNatick, Massachusetts 01760

BIT480The 480 has a maximum capacity of 65k

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bytes, a minimum of 1,024. Memorycycletime is 3 microsec; word length is 8 bits(variable). The machine has eight hardwareregisters (no index registers) and oneaccumulator. Maximum DMA wordtransfer rate is 250 kHz. The basic softwareincludes two assemblers, onemac roassembler, editor routines, areal-time executive monitor, and ASAbasicFORTRAN, which requires 8k memory.The only peripheral device required is anASR-33 teletypewriter. Operations with afew of the I/O devices are as follows:paper-tape reader and control, 60 or 30characters/second; paper-tape punch andcontrol, 60 characters/second; incrementalmagnetic tape and controller operates at300 steps/second 200 bpi; digital magnetictape transport operates at 200, 556, or800 bpi at 35 ips. The rack is about10-11 in. high. Price of the basic unit withASR-33 and a Ik memory is $7,100. With4k it is about $9,300.

BIT483The BIT483 is a newer and less

expensive model than the 480. The basicunit price is $6,900 with Ik, $7,130 for2k, and $9,310 for 4k with ASR-33.Thememory is expandible to 65k. Bothmachinesare I/O-compatible, and programsprepared for the 480 will operate the 483.Four interrupt levels are offered, and the483 provides peripheral and transferinstructions unavailable in the oldermachine. Memory cycle time is.98 microsec, full word store time is4 microsec, and add time is variable. Wordlength is 8 bits/word (variable). There are125 instructions, with one addressper, and4 to 32 priority interrupts. Maximumtransfer rate is 1 MHz. Peripheral optionsinclude a punched card input of 200cards/minute with the output at 100cards/minute, up to 15 million bytes ofmass storage, a 30O-characters/second tapereader, a 450-1ines/minute printer, and aseven-channel magnetic tape (30 kCcharacters/second). Direct-memory-accesschannel is standard. Software includes atwo-pass assembler, Basic, FORTRAN, areal-time executive monitor, and a diskoperating system. The first BIT computerwas delivered about a year ago.

CincinnatiMilacronDepartment R·50Lebanon, Ohio 45036

CIP/2oo0Memory speed of the CIP/2000 is

1.1 microsec full cycle, 0.66 microsec halfcycle. The memory is 4,096 bytes (8- or9-bit), ex p a n d able to 32,768.Microprogramming allows the user toreorganize the instruction set by changing

the hard-wired read-only memory (ROM)in the control unit. ROM speed is 220 nsecper instruction, with 256 to 1,024 words inmodules of 256 16-bit words. TheCIP/2000 comes with one ROM board; upto three additional boards can beaccommodated at a price of $600 each,with programming. The machine has an8-bit parallel byte I/O bus for programmedand fully automatic concurrent transfers,and serial I/O interfaces for Teletypes orsimilar devices. Direct-memory-access(DMA) channel has a maximum transferrate of 909,000 bytes/second. There are 15general-purpose 8-bit registers, with 7working registers. Software includes aCross Assembler written in FORTRAN IVto generate microprograms for theread-only store. Instructions aremicroprogrammed to suit applications;there are 16 basic commands. The entireunit is enclosed in a cabinet 8% in. highand weighs 75 lbs. The 4k machine is$2,720.

CIP/2100The CIP/2IOO is an expandedversionof

the 2000, with variable-length instructions,a 16-bit accumulator, and variable 8-, 16-,24-, and 32-bit operations. The 2100includes six operational registers, 89instructions in the set, eight operandaddressing modes, a built-in bootstraploader, and one operand addressing up to 4bytes. Software includes a two-passassembler, an assembler written inFORTRAN IV, a tape editor, and aTeletype operating system. There are up to64 priority interrupts, expandable ingroups of 8. Price of the basic CIP/2000with 4k and Teletype is $6,162. TheCIP/2000 and 2100 were first shippednearly a year ago by the CincinnatiMillingMachine Company,now Milacron.

Clary DATACOMP Systems,Inc.404 Junipero Serra DriveSan Gabriel, California 91776

DATACOMP-404The 404 computer starts at $6,800, but

the price range can go as high as $85,000.Word length is IS-bit, memory cycle timeis 2 micr csec, and access time is.750 microsec. Word length operatingmodes built into the hardware can beprogrammed for 16, 32, 48, or 64 bits,doing away with multiprecision routines.Sixteen addressing modes includedouble-index and relative. Hardwaredecimal arithmetic includes multiply anddivide, with automatic scaling. There are15 to 256 priority interrupts. On I/O,automatic forrnating eliminates editingsoftware. The 404 executive hardware

Behav. Res. Meth. & Instru., 1970,Vol. 2 (6)

time-shares its own terminals while actingas an intelligent terminal in a time-sharednetwork. Executive time-share softwareserves 2 to 16 users.

Pricing of the System 404, with a4k x IS-bit memory, decimal arithmetic,hardware editing, and Teletype controller,is $8,700. Deliveries have been made forover a year.

Compiler Systems, Inc.P,D.Box 366Ridgefield, Connecticut 06877

C81-16and C8I-24Designed for the execution of high-level

languages, CSI-16 and CSI-24 have fourlevels of operating systems available. Theseare batch, time sharing, andmultiprogramming with disk-resident orcore-resident programs. According to themanufacturer, only 4k of core is neededfor time sharing the most complexoperating system, Offered are a one-passassembler, Basic, Algol, andFORTRAN IV, which supposedly operatein less than 4k of core. Various utilities areoffered also. The number of instructions is32 for both machines. Add time is1.8 microsec. Number of priorityinterrupts: 4 to 256. The CSI-16 is a 16-bitprocessor with a memory of up to 32k.Price of the basic unit is $10,750.

The CSI·24, priced at $14,950, is a24-bit processor with a maximum of 32k.This computer has the ability to access upto eight million words of direct-accessmemory. Input/output is handled by aseries of up to 256 microprogrammedprocessors. Floating-point hardware isincluded in the cost of both machines. Alsoavailable: Teletype cassette tape, disk,drum, and line printer. Cycle time is1 microsec for both computers. Rackheight is 21 in.

Computer Automation, Inc.895 West 16th StreetNewport Beach, California 92660

POC-80Sand 816Basic word size for the PDC-808 is 4k

expandable to 16k. Word length is 8 bitsand memory cycle time is 8 microsec.Operation is parallel, single address, andutilizes a random access. The machine hascore memory, eight hardware registers, anda party line I/O bus. There are. twopriority-interrupt lines as well as a requestline. Additional interrupt lines are availablein groups of eight. The number ofhardware instructions is 73, with one andtwo addresses per instruction; number ofpriority interrupts, 3 to 64. Punched cards

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

can be input at the rate of 300/minute andoutput at 100/minute. The optionalmagnetic tape handles 8 or 10 kCcharacters/second. The basic Model808sells for $4,990. Over 100 machines havebeen sold.

The PDC-816 is priced at $9,980, amarkdown. (Original price wasapproximately $13,800, includingASR-33.) The basic configuration is 4kwords also. Word size is 16 bits andmemory cycle time is 8 microsec. Full­word add time is 16 microsec, as comparedto the 808's 24 microsec. Maximum DMA

word transfer rate is 125 kHz. Number ofpriority interrupts: 3 to 64.

The 808 entered the market in 1968, the816 about a year later.

POC-208and -216; POC-I08 and -116The 208 and 216 are newer computers,

8- and 16-bit, respectively. Both machinesoffer 2.6-microsec memory cycle times,compared with 8 microsec for the originalmodels. Three new instructions have beenincorporated into the 208 which were notin the 808. In Model 208, an addinstruction can be performed in8 rnicrosec; the 216 can do the job in5 microsec. Maximum word transfer rate is250 kHz for the 208 and 800 kHz for the216. The four machines, 808, 816, 208,and 216, are compatible in all peripheralgear and software. Rack height is 8.75 in.

Model 208 sells for $5,990. The 216 hasrecen tly be en reduced by nearly$S,OOO-from $12,890 to $7,990. The 216has 42-microsec software multiply, 122instructions, three levels of hardwarepriority interrupts, automatic I/Omultiplexing, SOO,OOO-bytes/second I/Oblock transfers, indirect and indexedaddressing, two accumulators, an indexregister, and 4,096 x 16 core memory.Both machines have been around for aboutI-Hi years.

The PDC-108 (8-bit) and -1l6 (16-bit)computers have just been introduced. Bothhave 1.6-microsec cycle times.

Computer Development Corporation3001 South Daimler StreetSanta Ana, California 92705

CD-200A lk version of the CD-200 sells for

$3,500. The small processor has a1.2-microsec cycle time, with lk to over60k 8-bit bytes of memory. Add time is2.0 microsec. The number of instructions is69, and addressing is direct. Number ofpriority interrupts: 16. Software includesan assembler and a simulator to enable oneto write and test CD-200 programs onlarger computers.

The machine utilizes a flexible universalbus and provides an asynchronous memoryinterface, which permits various sizes,speeds, and types of memory to be used.The CD-2OO controls processor speed andinstruction execution time, and theuniversal bus allows direct memory accessfor peripheral devices and communicationbetween peripherals without going throughthe central processor. The computer is anew addition to the field.

Computer Logic Systems, Inc.49 Pollard StreetNorth Billerca, Massachusetts 01862

CLS-18The CLS-18 computer is new and priced

at $9,870 for the basic 4k unit. Wordlength is 18 bits, with the 4k memoryexpandable to 32k. Memory cycle time is0.96 rnicrosec, add time is 1.9 microsec,and multiply is 7 microsec. The machinehas 120 instructions, with the addressingbeing direct, indirect, extended, indexed,and push-pop. The number of priorityinterrupts is 8 to 144. DMAchannels: 1 to8. Maximum I/O is 1,250 kbytes/second.Software includes FORTRAN IV and atwo-pass assembler.

Control Data Corporation8100 34th Avenue, SouthMinneapolis, Minnesota 55420

CDC-1700The CDC-1700 is one of the

higher-priced small machines, with thebasic system price, with 4k, at $29,000.Adding an ASR-35 brings the price up toapproximately $35,000.

Memory cycle time is 1.1 microsec andword length is 18 bits. Minimum memorysize is 4k; maximum is 32k. Full-word addtime is 2.2 microsec; hardware multiplytime is 7 microsec. The maximum DMAword transfer rate is 900 kllz,

SC-1700The SC-1700 has 4,096 words of 18-bit

memory and can either operate as astand-alone system or assist the CDC-17oo.The SC machine has a 1.5-microsecmemory cycle time, a 3.Q..microsec addtime, 196 real-time-oriented hardwareinstructions, two hardware index registers,hardware multiply/divide multilevelindirect addressing, and multilevelhardware interrupts with program priorityassignment. In tandem with other CDCcomputers, this machine can operate as asatellite data preprocessor or concentrator,and can provide control applications.Software for the CDC 1700 series can be

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used, including an assembly system, tapeFORTRAN, mass storage FORTRAN, andmacroassembler (COMPASS). The SC-1700can be used alone for process control andgraphics. The 4k memory can be expandedto 32k, with each 4k increment costing$4,500. Basic price for the 4k SC-1700 is$15,900. Deliveriesbegan in mid-1970.

Datacraft Corporation776 N.E. 40th CourtP.O. Box 23550Fort Lauderdale, Florida 33307

DC-6024The basic price of the DC-6024 is

approximately $29,800, but the machine isadvertised as providing rapid memoryaccess an d a real-time capabilityapproaching that of a multiprocessor orlarger-scale system. The basic systeminclude s five 24-bit general-purposeregisters, three of which may be used forindexing, and a 8,192-word memory withparity expandable to 65,536 words inincrements of 8,192. Hardwaremultiply/divide/square root, four levels ofpriority interrupt, and a basic softwarepackage are included also. Memory cycletime is 1.2 rnicrosec with 24-bit word size.Full-word add time is 2.4 microsec.Maximum word transfer rate is 834 MHz.An ASR-33 is part of the basic I/Ostructure. The instruction set includesmore than 500 discrete operations.Software: FORTRAN IV. TheModel DC-22 magnetic core memory isavailable with 750-nsec cycle time.

Data General CorporationRoute 9Southboro, Massachusetts01772

NovaNova is a 16-bit machine with four

accumulators, two of which may be used asindex registers. It offers a choice of core orread-only memory of lk, 2k, 4k, 8k, andup to 32k (using an optional expansionchassis) 16-bit words. Direct addressing isrequired for the balance of memory.N umber of instructions: 200. Totalmemory cycle time depends on the type ofmodule accessed; 2.6 microsec is requiredfor a 4k module, 3.9 microsec for a 2kcore, 6.5 microsec for a lk core, and2.4 microsec for a 1k read-only module.With a 4k core module, typical addinstruction time is less than 5.9 microsec.Up to 62 devices may be connected to theI/O bus and may be individually selectedby the central processor.

Nova comes in desk-top console or a

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5~-in.-ta11 standard rack-mount package.Both basic versions can hold up to 20k16-bit words of memory or interfaceswithout expansion chassis. The standard 4kconfiguration with Teletype interface waspriced at $7,950.

SupernovaSupernova has the same basic

configuration as the Nova: 16-bit word,four accumulators, interchangeable coreand read-only memory, and the samepackaging design. This computer, however,is considerably faster than the Nova. A fullmemory cycle using core takes 800 nsecfor the Supernova (2.6 microsec for theNova). Usingread-only memory, cycle timeis 300 nsec for Supernova and 2.4 microsecfor the Nova. Supernova overlaps the fetchand execute portions of arithmetic andlogical instructions from read-onlymemory, so two numbers can be added inone 3QO-nsec memory cycle. The machineoperates in fully parallel fashion on its16-bit words-all 16 bits at once in a single3QO-nsec machine cycle. With the Nova,the word is divided into four 4-bit nibblesthat require four 4()(}.nsec cycles toprocess.

With 4k of core memory, Teletypeinterface, and automatic program load,Supernova had been priced at $11,700. Asof August I, 1970, a new price of $9,600was announced for the same configuration.The Supernova central processor has beenreduced from $6,850 to $5,600, and 4k16-bit memory subsystems have beenreduced from $4,500 to $3,650. TheASR-33 is priced at about $1,400.Muliply/divide and memory protection areoptions.

Recently, at the 1970 Spring JointComputer Conference, Data GeneralCorporation announced a new softwarepackage. Before this time, Basic had beenoffered for both machines. The newsoftware includes a complete ALGOL 60,two varieties of FORTRAN IV, and adevice-independent disk operating system.

Nova was announced in 1968 and firstshipped about 2 years ago. The Supernovawas introduced in 1969 and the firstmachines were delivered in 1970. Bothmodels are sellingexceptionally well.

Datamate Computer Systems, Inc.P.O. Box 310BigSpring, Texas 79720

DM-16The Datamate 16 is a 4k computer,

expandable to 32k, with parallel 16-bitoperation. Memory cycle time is1.0 microsec, add time is 2.0 microsec, andmultiply time is 5-7 microsec. DMA is 16

megabits/second. The machine has sevenhardware registers and 115 instructions. Ithas eight levels of nested, self-identifyingpriority interrupts, Held expandable up to64 levels. Priority interrupts have2-microsec response times. Softwareincludes a macroassembler, symboliceditor, library routines, on-line debug, andUSA Standard Basic FORTRAN.

The main frame weighs 501bs and is5~ in. high. The 4k unit was priced at$14,900; increments of 4,096 words cost$6,500. As of September I, 1970, an 8kcomputer costs $14,900 and increments of4,096 words are $4,500.

DM-70The DM-70 is a new machine (first units

delivered in mid-1970), named the SkinnyMini, which is small in size and low inprice. The cabinet is 1*in. high x 19 in.wide x 20 in. deep.

A 16-bit computer, the Datamate 70 has11 registers, 4 of which are 16-bitarithmetic accumulators, with twoavailable as index registers. An index I/Oregister is included also. A wide range ofoptional memories include a 1.0.ffiicroseccore, plus semiconductor memories of theread-only and read/write type, whichoperate at much higher rates. Directmemory access is built in. Over 144instructions are included in five classes ofmicroprogrammed format.

The machine is expandable to 32k with1.00microsec add/subtract. DMA rate is 16megabits. A symbolic editor, relocatingloader, I/O drives, diagnostics, and a debugpackage are included.

The basic Datamate 70 is housed in the1*in-high cabinet. The unit may includethe CPU, full power, and up to 1,024words of ROM, 256 words of scratch-padmemory, plus space for I/O devicecontrollers. For applications requiringextended memory, a 5%-in-high packagehouses the above plus 16k of core memory.The basic 4k computer sold for $6,400; itis now $6,100.

Data Technology Corporation1050 East MeadowCirclePalo Alto, California 94303

DR-1600The DT-1600 computer is a 16-bit-word

machine with 4k memory expandable to32k. Memory cycle time is 8.0 microsec.The machine has 73 hardware instructions.I/O devices include paper tape, disk, andmagnetic tape; incremental mag tape andcontroller (800 bpi IBM-compatibleread/write) is priced at $9,950. Theinterface electronics alone is $1,900. The

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

basic 4k DT-1600 costs $6,600 includingprocessor, console, and. power supply, 73instructions, power for up to 16k, twopriority interrupt lines, block transferability, and software package. Anadditional 4,096 words of memory costs$2,200. Rack height is about 9 in.

Decade Computer Corporation7457 Lorge CircleHuntington Beach,California 92647

Decade 70/2Memory cycle time for this machine is

.860 microsec and word length is 18 bits.Minimum word size is 4k expandable to16k. Full-word add time is 1.9 microsec;hardware multiply time is 6.5 microsec,divide time is 12.5 microsec. The machineh as one accumulator, five hardwareregisters, and one memory index register.Maximum DMA word transfer rate is1.1 MHz; maximum number of externalinterrupts is 32. The basic system with 4kwords is $12,800. An ASR-33 Teletypecosts $1,200. FORTRAN IV is available, asis the conversational compiler CHAT.Various I/O peripherals are optional.(Refer to the Redcor 70 for a descriptionof the Decade 70 machine.)

Digiac CorporationAmes CourtPlainview,New York 11803

Digiac·3080The Digiac-3080 is a drum machine with

a word length of 25 bits for a basic 4kmemory. Price is $19,500 for a unit with50 hardware instructions and software thatincludes FORTRAN.

Digital Computer Controls, Inc.Fairfield, New Jersey 07006

DCC-1l2The Model DCC-1l2 is a newly

announced 4,096-word (expandable to32,768) general-purpose minicomputerwhich features 1.2 microsec random-accesstime, an arithmetic processor, and abuffered I/O control. The unit alsoprovides eight auto-index registers, indirectaddressing, and a high-speed channel.DCC-1l2 is advertised as hardware-,software-, and plug-compatible with DEC'sPDP~ family, with l.5-microsec cycletime.

Digital Equipment Corporation146 Main StreetMaynard, Massachusetts 01754

A number of the earlier DEC machines

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

may be .found on the used-computermarket, e.g., the dated PDP-I, PDP-5,PDP-7, LINC-8, and PDP-S. Two of thesewill be described briefly before proceedingto the other computers on the DigitalEquipment Corporation list.

The PDP.5, for example, includes a CPU,1,024- to 32,768-word, 12-bit randomaccess, magnetic core memory, I/O control,and I/O tape teleprinter. Standard featuresinclude a FORTRAN compiler, symbolicassembler, 12-or 24-bit arithmetic, indirectaddressing, data and program interrupts,and eight auto-indexing core memorylocations. Memory cycle time of the PDP-Sis 6 microsec.

The popular LINC-8 comprises twosubsystems, a standard PDP-8 and theLINC. The two subsystems share a dualconsole and are connected by means of aspecial interface section which mediatesexchange of data and control. The LINC-8was designed to operate in one of twomodes. In the first mode, it operates as aLlNC having certain special in-out andspeed characteristics but otherwiseidentical with the original LlNC(Laboratory Instrument Computer). TheLINe and the PDP-8 are bothsingle-address, fixed-word-length, parallelcomputers using 12-bit binary arithmetic.Cycle time of the 4,096-word core memoryshared by both computers is 1.5 microsec.This cycle time in either mode provides acomputation rate of 333,333additions/second. In the LINC mode,multiplication is carried out inapproximately 32 microsec. The 4k core isexpandable to 32k. Standard equipmentfor the LlNC-8 includes an ASR-33teletypewriter, audio control, cathode rayoscilloscope, dual magnetic tape unit, a6-bit relay register, and a data terminalpanel, behind which are provisions formounting 60 Flip Chip modules as well asII I/O signal lines. A standardana log-to-digital converter has 16multiplexed channels, with 16 additionalchannels optional. Standard cabinet size:69-1/8 in. high x 32~ in. wide x 33 in.deep.

PDP·8PDP-8 computers are found in all sorts

of laboratories, but the machine has beensucceeded by other computers in the series.There are, however, a tremendous numberof the units in use.

The PDP-8 is a 4k computer, expandableto 32,768k, with a word length of 12 bitsand memory cycle time of 1.5 microsec.Programmed I/O data transfers are handledat up to two million bits/second.Device-initiated I/O transfer rates are up to7.9 million bits/second. The machine canservice up to 64 external devices, eachrequiring up to three commands, and 96

devices, each requmng two commands.Software includes FORTRAN andmathematical subroutines. Theprogramming system also includes theMACRO-8 symbolic assembler, symbolicon-line debugging, tape editor, and afloating-point package. The basic systemincludes 4k words, keyboard printer andtape re ader-punch, eight auto-indexregisters, Wired-in analog-to-digitalconverter, program interrupt, datainterrupt, and indirect addressing. Originalprice of the system was about $18,000.

PDP-8/SThe PDP-8/S has been succeeded by

later models also. With many of the PDP-8features and fully compatible, this unit hasslower speed and is less expensive. The4k-expandable-to-32k memory has amemory cycle time of 8 microseccompared to the PDP-8 1.5-inicrosec time.Add time is 36 microsec vs 3 microsec forthe PDP-8.

The 8/S sold for slightly less than$10,000, and is smaller in physical sizethan the PDP-8. Memory size, I/Ocapabilities, standard options, and softwareare the same as the PDP-8. An ASR-33Teletype is standard.PDP-8/1

The PDP-8/1 has most of thecharacteristics of the PDP-8, except forexpanded software, new options, a newmethod for interfacing, and a lower price.

External devices are interfaced to thePDP~/I via a flexible I/O bus so the centralprocessor does not have to be modified.Built-in instruction capability provides aconvenient method for checking the statusof peripherals. Data is transferred betweenthe external devices and computer byprogram interrupts, programmed datatransfers, and data break transfers. Theuser chooses the most efficient method,depending on I/O requirements.

Cycle time is 1.5 microsec, add time is3.0 microsec, and subtract takes6.0 microsec, as with the PDP-8. Anextended arithmetic option permitsmultiply/divide in approximately 6 and6.5 microsec, respectively, against 21.2 and37.2 microsec for the PDP-8. MaximumI/O is 500 kbytes/second. The machine haseight auto-index registers.

Pedestal model size is 36~ in. high x30 in. wide x 31-3/8 in. deep. The tablemodel measures 8~ in. high x 30 in. wide x31-3/8 in. deep. Rack-mounted size is30-7/8 in. high x 19 in. wide x 23-5/16 in.deep. Weight for all of the configurations is2501bs. An ASR-33 is standard for the 8/1system, which was introduced in 1967 andfirst delivered in 1968. Software includesFORTRAN, Pal-D, Basic, ALGOL, andMacro-8. Price: $12,500 withteletypewriter.

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PDP-8/LThe PDP-8/L is a smaller version of the

8/1. The internal plug-in expansion featuresof the 8/1 were left out to keep the priceand size down. Expansion of core memoryfor the PDP-8/L is limited to 8,192 (doubleits basic core of 4k) with l2-bit wordlength. And the memory cycle time isslightly lower at 1.6 instead of1.5 microsec. The machine also requiresexpansion options to add most of theinput/output peripherals that plug into the8/1. Both have eight basic instructions, sixmemory reference and two augmented.Software packages are the same.

Physically, the table model of the 8/L is8* in. high x 19 in. wide x 20* in. deepand weighs 831bs. The rack-mountedmodel is 3 in. deeper and weighs 70 lbs.The ASR-33 is standard. Basic price is$8,500.

LAB-8The LAB-8 is a signal averager featuring

the PDP-8/L computer with ASR-33teleprinter. AX08 laboratory peripheralsinclude: 4 channels of analog-to-digitalinput (expandable to 24), 9-bit conversionat all sampling speeds, sample and holdcircuitry, two Schmitt trigger inputsexpandable to three, one pulse output, a19-kHz crystal clock, a variable-frequency(I6-Hz to 200-kHz) RC clock, an X-Vdisplay and plotter control. An RM503oscilloscope is used as an X-V display forcomputer output. A number of options areavailable for extending capabilities. TheLAB-8 can also include the PDP-8/1 withthe AX08 lab peripheral. The system waspriced in the $20,000 range with actualprice dependent on computer (S/I or S/L)and options.

PDP·8/EThe PDP-8/E is the most recent addition

to the 8 series and is upward-compatiblewith PDP-8-series software and peripheraldevices. At the heart of the PDP-8/E is aparallel bus organization board. The lattereliminates all cross wiring. Circuit boardsare plugged in above the 10.5-sq-in.organization board, including threememory boards (4k), four processorboards, a Teletype control board, a consoleboard, and a PDP-8-compatible I/O board.

Memory cycle time for the 8/E is1.2 rnicrosec, add time is 2.6 microsec, andmultiply is 7.4 microsec. Maximum I/O is830 kbytes/second. The computer isbyte-oriented (6 bits) and has a 12-bitword. An optional read-only memory isavailable in 256-word increments. ThePDP-8{E has 23 instructions with directaddressing, up to 12 direct-memory-accesschan nels, and up to four priorityinterrupts. The basic computer with 4k

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memory is priced at $4,990. With ateletypewriter, it is $6,500. Additionalmemory can be added up to the 32kmaximum at $3,000 per 4k.

PDP-9/LThe PDP-9/L is a smaller, slower version

of the PDP-9. It is also cheaper. Price ofthe basic system with ASR-33, 4k memory,and cabinet is $19,900.

The PDP-9/L has 4,096 18-bit words ofcore memory, expandable to 32,768words. Memory cycle time is 1.5 microsec,add time is 3 microsec, multiply is13 microsec, and divide is 14 microsec. Themachine has directly addressable memory,eight data channels, auto-index registers,and an automatic program loader in thebasic model. The 4k standard softwareincludes a two-pass assembler, utilityprograms, editor, math package, anddebugging. With Sk memory or more, the9/L can accept advanced PDP-9 software,including FORTRAN IV, amacroassembler, symbolic editor, I/Omonitor, and others. A statistical packagewritten in FORTRAN (STATPAC) and atranslater package, making it possible toadapt a major part of the code written forthe PDP-S family of computers, wereintroduced in 1969. Expanded to 16k, themachine has capability forbackground-foreground programming. Thatis, program development can be carried outalong with on-line activities.

In comparison, the PDP-9 has an 18-bitword length, with a basic 8,192-wordmemory expandable to 32,76S in8,192-word increments. Cycle time is1.0 microsec, add time is 2 rnicrosec, andI/O transfer rate- is up to 18,000,000bits/second. Standard equipment includes apaper-tape reader, a paper-tape punch, andan ASR·33 Teletype.

PDP-H/20The PDP-11/20 was first delivered to

customers in early 1970. It is a16-bit-word-Ien gth c ompu ter with4k-expandable-to-8k memory. Memorycycle time is 1.2 rnicrosec, add time is2.3 microsec, and multiply is 4.5 microsec.Maximum I/O is 1,660 kbytes/second. Themachine has four levels of priorityinterrupts, expandable to 256, and 400hard-wired instructions with directaddressing. The general registers areprogram-accessible. Software routinesavailable include assembler, Basic, andFORTRAN. Price of the unit with 4kmemory, console, and ASR-33 Teletype is$10,800. The table-top model is 11 in. highx 20 in. wide x 24 in. deep and weighs1001bs. The rack-mounted model is1O~ in. high x 19 in. wide x 23 in. deepand weighs 90 Ibs.

PDP-I2The PDP-12 is a complete laboratory

system with a large display (7 x 9 in. CRT),16-channel A/D converter expandable to32, and two tape units. The computer has a4k memory, expandable to 32k, withl2-bit word length. Memory cycle time is1.6 rnicrosec and add time is 3.2 micro sec.Hardware multiply is standard. Maximumword transfer rate is 625 kHz. There are 43basic instructions, 12 hardware registers,and 15 auto-index registers.

Advertised as the successor to theLINC-8, the PDP-12 is faster and morepowerful, yet $10,600 less. The PDP-12has buffered I/O, including a mag-tapeprocessor. The display-based programmingsystem is not difficult to use for PDP-12programs, LINC-S, or PDP-8 programs. Themachine can execute two completeinstruction sets, the LINC and the PDP-8family of instructions. A signal averagingprogram requires peripherals and allows forhandling up to 1,024 data points per sweepand the averaging of the data over amaximum of 4,096 sweeps. FORTRAN,FOCAL, and floating-point packages areavailable. Standard cabinet size is 69 in.high x 32~ in. wide x 33 in. deep, and theweight is 500lbs. The table model isslightly smaller. For about $29,000, thesystem includes a 4k memory, a DMAchannel, LINCtape automatic control, twomag tape transports, LlNCscope controland character buffer, CRT display, AIDconverter and multiplexer (16 channels), adata terminal panel, and ASR-33teletypewriter.

PDP-I4The PDP-14 was announced by DEC in

March of 1969. The machine has modulardesign with 1,024 nondestructive l2-bitread-only memory, expandable to 4,096 inblocks of 1,024 words. The interface unitis expandable in blocks of 32 inputs to256. Output interface is expandable inblocks of 16 outputs to 255. A computerinterface is available between the PDP-14and the PDP-8/I or 8/L machines. Themachine is 24 x 18 x 8 in. and weighsSO lbs, excluding interfacing.PDP-IS/I 0

The PDP-1511O is an l8-bit-word-Iengthcomputer with 4k basic, expandable to131k. Memory cycle time is 0.80 microsec,add time is 1.6 microsec, and multiply is7.4 microsec. The machine has 28 priorityinterrupts, expandable to 64, and eightDMA channels. Addressing is direct to 4kwords and indirect to 32k. Two memorycycles are required for indirect. There arenine hardware registers, one index register.The machine is the basic PDP-IS and canbe expanded to capabilities of largersystems.

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

Software includes FOCAL, a two-passassembler, Basic, and FORTRAN IV. Areal-time executive monitor is optional.Price of the computer is $16,500 with 4kand a teletypewriter. An additional 4k ispriced at $6,000. The units were firstdelivered to customers in early 1970.

The 18-bit PDP-IS is offered in fourconfigurations. An advanced monitorsystem is priced at $36,000; one designedfor background/foreground applications, at$58,000; a large, disk-basedbackground/foreground system sells for$92,000. The PDP-15/30 is abackground/foreground system developedfor use where one or more real-time taskstypically require continuous responsivenessfrom the computer but do not use itsentire capacity. The system includes a16,384 core memory, magnetic tapestorage, and a wide range of software.

Digital Scientific Corporation11455 Sorrento Valley RoadSan Diego, California 92121

Meta 4The Meta 4 is a 16-bit-word computer

with a 4k memory expandable to 65k.Memory cycle time is 0.90 microsec, addtime is .90 microsec, and multiply is3.0 microsec. Addressing is direct, with 27instructions. There are nine DMA channelsand 6 to 32 priority interrupts. MaximumI/O is 2,400 kbytes/second. Softwareincludes a batch monitor and a real-timeexecutive system. Price of the 4k unit is$15,650. First deliveries were made inearly 1970.

Dresser Systems Inc.P.O. Box 2928Houston, Texas 77001

Dresser8000The 8000 has 16-bit word size with 4k

memory expandable to 16; cycle time is4.0 microsec. There are 27 hardwareinstructions, two priority-interrupt levels,and two direct-memory-access channels.Software: loaders and real-time monitor. A'CRT and ASR-33 Teletype are included. ASelectric and card reader are available asI/O devices.

Elbit Computers, Ltd.9701 North KentonSkokie, Illinois 60076

or

Elron, Inc.Building812Raritan CenterEdison, New Jersey 08811

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

Elbit-l00The Eibit-IOO is a 12-bit machine with a

basic memory size of lk expandable to 4k.The computer has 16 hardware instructionsp 1us mod ifiers, and cycle time is2 micro sec. Full-word add time is7 microsec. There are four priorityinterrupts. I/O devices include Teletype,interface to the IBM-360,paper-tape readerand punch, magnetic drum, A-to-D andD-to-A converters, disk and line printers.Software: logic operations, conversationalmodified FORTRAN, and DEBUG. Priceof the basic unit is approximately $6,000.About 2 years ago, the Elbit-100 wasadvertised at $4,900 by Elbit Computers,Ltd., 88 Hagiborim Street, P.O. Box 5390,Haifa, Israel. Rack height is 9 in.

Electronic Associates, Inc.185 Monmouth Park HighwayWest Long Branch, New Jersey 07764

EAI-640The EAI-MO has a core-type memory,

8k expandable to 32k, with 16-bit wordlength. The basic 8k unit costs $24,500,including ASR-33. Memory cycle time is1.65 microsec, add time is 3.3 microsec,and multiply time is 18.1 microsec,Maximum word transfer rate is 600 kHz.The machine has M hardware instructionswith multilevel indirect addressing and 10hardware registers. Software includesFORTRAN IV, an interpreter, andmonitors. The unit was first delivered over4 years ago and is not one of the smallerrack-sizemachines.

EMR Computer8001 Bloomington FreewayMinneapolis,Minnesota 55420

Advance EMR·6120The 6120 is a 16-bit-word computer

with 4k basic, expandable to 32k. Cycletime is 2 microsec and the machine has 60hardware instructions. I/O devices includeTeletype, paper and mag tapes, disk, andcommunications interface. Basic price isapproximately $7,700.

Advance EMR-6130The 6130 is a much more expensive

machine at $46,000, with 8k words, and ismerely noted for comparison. Memorycycle time is .775 microsec, with an 18-bitword length. Minimum word size is 8kexpandable to 32k. The 32,768 words canbe addressed directly in 1.9 microsec andaddressed indirectly in 2.9 microsec. DMAword transfer rate is 1.2 mHz.

FOTO·MEM,Inc.6 Strathmore RoadNatick, Massachusetts 01760

CENTAURThe basic CENTAUR includes the CPU,

a 4,096-byte memory, ASR-33 Teletype,and a basic software package on papertape. Memory cycle time is 980 nsec andthe unit includes eight programmablehardware registers, a 17-bit accumulator,and a 16-bit index register. Seventy-eightbasic machine instructions include 15memory reference instructions. The basic4k memory is expandable in modules to65k, 536 bytes. Addition of memory datato the accumulator is accomplished in3.0 microsec (4.0 microsec indouble-precision mode). Multiply time is7 microsec (l6-bit product). In directmemory access, data can be transferred toor from memory at the rate of 800,000bytes/second or 250,000 bytes/second(alternate mode). Maximum transfer ratenormally is 141,000 bytes/second. Priorityinterrupts: four.

Up to 256 external devices areprogram-addressable, including mag tapestations, disk flles, monitoring consoles,printers, and the Foto-Mem 1/4-trillion-bitFM 390 MassMemory System.

The rack is 10.5 in. high x 10 in. wide x15 in. deep, and its weight is 481bs, with8k memory. Price of the basic unit is lessthan $10,000, with 4k and Teletype.

Four-Phase Systems, Inc.10420 North Tantau AvenueCupertino, California 95014

System IV/70 Video TerminalBy utilizing the computer memory space

to supply the electronics necessary forcharacter generation, the Series Foursystem can offer video terminals for$2,500 each. The basic system costs$16,000 with deliveries beginning in thefourth quarter of 1970. The basic contains6,144 bytes, 24-bit words of core memorywith 1.9-microsec cycle time,15.2-microsec add/subtract, and ROM maybe substituted for 12 kbytes of RAM. Thesystem is expandable to 98 kbytes. Atmaximum, 32 terminals can be operated ina time-sharing system. The video terminalsinclude alphanumeric keyboard. Displaycapacity is 50 lines with 48 characterseach. The 117 instructions include byte aswell as word manipulation. The system willinterface with teletypewriters, disks, tapes,card readers, and mag-tape cassettes.

Fujitsu Ltd.680 Fifth AvenueNew York, New York 10019

279

or

Fujitsu Ltd.8,2-chomeMarunouchi, Chiyoda-kuTokyo, Japan

FACOM-RWord length for the FACOM-R is 17

bits, 16 data bits plus parity, and memoryspeed is 1.5 microsec. Capacity is 4kminimum, expandable to 32k. There are 28basic instructions within seven classes.Addand subtract speeds are 6 microsec withoutaddress modification and 7.5 microsec withmodification. The machine has four indexregisters. Maximum data transfer rate is800 kbytes/second for interface mode.Number of priority interrupts: one. Thenumber of I/O unit addresses is 255maximum. All of the standard I/O devicesare available. Software includes FASP(FACOM Automatic Symbolic Program)and mini-FORTRAN. The rack isapproximately II in. high and 23 in. deep.Basic system cost (4k) is approximately$10,000.

General Automation, Inc.706 W. KatellaOrange, California 92667

SPC-12The standard SPC-12 computer includes

a 4,096 by 8-bit word memory expandableto 16,384 words, with full cycle time of2.16 microsec. Features include a paralleladder, six addressing modes, eight 12-bithardware registers (including anaccumulator, an index, and twoindex/accumulator registers), SO basiccommands, a priority-interrupt system, arelative-time clock, and a Teletypeinterface for approximately $5,000.Maximum DMA word transfer rate is430 kHz. Add time is 4.3 microsec, accesstime is 600 nsec. A substantial library ofreal-time monitors, a one-pass assembler,executive control systems, process controlfunctional programs, utility routines, andI/O drivers are operational and maintainedfor SPS-12 user projects. The unit weighs29lbs and is SY<! in. high x 17~ in. wide x20 in. deep.

GA 18/30The Model GA 18/30 is

software-eompatible with IBM's 1130 and1800, hence the designation 18/30. Thesystem has a 16-bit word length, single-anddouble-precision arithmetic hardwaremultiply, divide plus parity and storageprotection bits. The processor has a960-nsec memory available in 4kincrements to 32k and a 16-word 3S-nsec

280

scratch pad. There are six classes ofinstructions with over 400 modifications.Add time (single precision) is 2.4 microsec,multiply time is 12.0 microsec, and datachannel transfers, 1.2 microsec. Maximumword transfer rate is 960 kHz. Software isprogram-compatible with the two IBMmachines and includes FORTRAN,assemblers, and real-time executives. Priceof the basic system is about $18,000; thecost is $19,500 with ASR-33. The unittakes 19 x 15-% x 22~ in. of rack space andweighs 85 to 1051bs. depending onoptions.

SPC-16The SPC-16 is the newest computer in

the General Automation line and has abasic price of $10,000. The machine has a950-nsec memory cycle time and a 4k Corememory expandable to 32k. Read-onlymemory has a 480-nsec cycle time. TheSPC-16 has 16 programmablegeneral-purpose registers, and up to 64hardware priority interrupts. The machinecan do both single- and double-wordaddressing, direct or indirect, and addressup to SI2k bits, up to 6Sk bytes, and up to32k words. As many as 64 external deviceswith 200 control functions can be operatedthrough the parallel I/O bus. Servicesoftware includes real-time executivesy stems, disk executive system,FORTRAN, and others. The unit weighs80lbs maximum and measures 10.5 in.high x 19 in. wide x 23.6 in. deep.

General Electric Information Systems1285 Boston AvenueBridgeport, Connecticut 06602

GE-PAC 30-1 and 30-2The average purchase price for either of

these systems is approximately $11,800.Both computers have 16-bit word lengths,a maximum memory capacity of 64k, ISindex registers, and up to 256 CPU I/Ochannels. Memory cycle time for the 30-1is 1.0 rni cr osec , for the 30-2,0.67 microsec. Access times are the same.The 30-1 has 27 instructions and the 30-2has 93. Software includes interactiveFORTRAN.

GRI Computer Corporation76 Rowe StreetNewton, Massachusetts 02]66

GRI-909The basic computer, with 4,096 words

of 16-bit random-accesscore memory, sellsfor about $8,000. The GRI-909 features aI 6-bit fully parallel processor withI.76-microsec cycle time. The 32,768

words of memory are directly accessible;minimum core size is 1,024 words. Sixteenlevels of interrupts are available, and morethan one device can be operated at eachlevel. The number of instructions is 100,and the addressing is direct. Theoreticallimit of instructions is 50,000. I/O rate:direct memory access or device to device at568,000 16-bit words/second maximum.There are II registers in the basiccomputer, which is mounted in a cabinet1O~ in. high and 20 in. deep; weight isapproximately 501bs. The machine hasbeen shipped to customers for about ayear.

Input/output data and control buses(groups or parallel wires) on whichperipheral equipments reside extend insidethe computer. All of the internal computerelements are connected across these buses.

Hewlett-Packard Company1501 Page Mill RoadPalo Alto, California 94304

HP-2114BThe Hewlett-Packard 2114B is a

16-bit-word computer with4k-expandable-to-8k memory. Memorycycle time is 2.0 microsec, add time is4.0 microsec, and subtract is 6.0 microsec.The machine has 1,024-word page size,with direct address for two pages andindirect address for any page. Theprocessor has 70 one-word instructions,microprogramming of up to eightinstructions. Two addressable accumulatorsare used to simplify programming. Thereare seven plug-in I/O channels in the mainframe plus 17 additional channels with anoptional I/O extender unit. Peripherals areinterfaced with plug-in cards. Interfacecards are available for many digitalinstruments and peripherals. Optionalmultiplexed I/O system allows interfacingup to 56 devices. A direct-memory-accesschannel is optional at a cost of $1,500. Thelatter has a maximum data transfer rate of500,000 16-bit words/second. Softwareincludes FORTRAN, ALGOL, Basic, atwo-pass assembler, and extendedassembly, most of which require 8kmemory. The basic 4k unit costs $8,500;an additional 4k is priced at $4,500. TheASR-33 is $2,000 and the I/O Extender ispriced at $3,500, with an additional$1,000 for the computer interface kit. Thebasic frame is 12 in. high x 16-% in. wide x24-3/8 in. deep and weighs 102 Ibs. Themachine was introduced in 1969.

HP-2115AThe HP-2ll SA is a 16-bit 4k-8k machine

similar to the HP-2l14B in speeds and

Behav.Res. Meth. & Instru., 1970, Vol. 2 (6)

other characteristics. This computer,however, has 8 external interrupts in thebasic system, expandable to 40. Price ofthe 4k unit is $14,500.

HP-2116BThe HP-2116B has an 8k memory,

expandable to 32k, with 16-bit wordlength. Memory cycle time is 1.6 microsec,add time is 3.2 microsec, and multiply is19.2microsec. The computer has 16priority interrupts in the standard package,expandable to 48. Maximum I/O is 600kbytes/second, The machine has 72 basicinstructions and seven hardware registers.Software includes FORTRAN IV, ALGOL,Basic, and a real-time executive. Price:$24,000. An additional 8k memory costs$10,000. Both the 2115A and the 2116Bhave been on the market a few years.

HoneywellComputer Control DivisionOld Connecticut PathFramingham, Massachusetts 01701

DDP-416 and DDP-SI6The DDP-416 and -516 offer basic

memories of 4,096 16-bit words and fullcycle times of 0.96 microsec. The formermachine is expandable to 16k and has 34basic instructions with five address modes.The latter unit is expandable to 32k andhas 72 instructions with eight addressmodes. The DDP-516 has floating pointand the -416 does not. Both computershave two external interrupts; the maximumnumber available is 48. The DDP-516software consists of over 250 programs,with the standard package containingFORTRAN IV (for a minimum of 8,192words of core memory), DAP-16 fortranslating from the programmer's tomachine language, and a real-time monitor.The DDP-416 has over 50 programscompatible with the -516. Both machineshave one- and two-pass assemblers.

Add time for the DDP-516 is1.92 rnicrosec and most instructions areexecuted in that time or less. Themaximum word transfer rate for bothmodels is 1.04 MHz. Dimensions are24 x 24 x 38 in.; weight is 250 Ibs.

Approximate price of the DDP-416 is$16,900, and the DDP-516 costs $25,000.An ASR-33 Teletype is included in bothprices.

H-316The H-316 is similar to the DDP-516 in

having the same register organization,instruction repertoire, and I/O interfacecharacteristics. Memory cycle time for theH-316 is 1.6 microsec and add time is3.2 microsec. Instruction complement is 72

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

with eight address modes. Word size is16 bits, with the 4,096-word memoryexpandable to 16,384 words. Thecomputer has seven hardware registers; sixcan be controlled from the front panel andthe seventh is an index register. The 16priority interrupts may be expanded to 64.More than 500 field-proven softwarepackages can be operated. Programsinclude FORTRAN IV,DAP-16 and I/Oselector, a disk-operated program (DOP)and EXEC-16, and executive controlpackage. The ISO-lb unit measures 14 in.high x 17'h. in. wide x 24'h. in. deep. Theprice is $9,700 without ASR-33, whichcosts an additional $1,700.

H-112The H-112 is a 12-bit stored-program

controller computer for on-line, real-timedata collection and reduction applications.The machine has a 4k basic memoryplug-in, expandable to 8k. Memory cycletime is 1.69 microsec and add is7.63 microsec. Five instruction types makeup 37 standard instructions. Addressing isindirect. Skip .instructions aremicroprogrammable. Input/output rate:one 12-bit word!3.39 microsec or 295kwords/second (direct data channel option).Standard software includes an assembler,debug, diagnostics, loader, and mathlibrary.

IBM CorporationArmonk, New York 10504

IBM-I130The IBM-I130 is a 16-bit-word machine

with a basic 4k memory, expandable to32k. Memory cycle time is 2.2 microsec,add time is 4.88 microsec, and hardwaremultiply time is 1.5 microsec.Direct-memory-access channel is standard;maximum word transfer rate is 460 kHz.The machine has seven hardware registers,three memory index registers. The basicsystem has six external interrupts; themaximum number available is 96. Softwareincludes a two-pass assembler, USASI,Basic, and FORTRAN IV. Price of the 4ksystem is $25,880, including an ASR-33and secondary storage. Additional 4kmemory is priced at $8,000. The "average"purchase price of a 1130 system is$68,000.

IMLACCorporation296 Newton StreetWaltham, Massachusetts 02154

PDS-IThe PDS-I is a programmable

stand-alone display computer system

priced at less than $10,000. The systemcomprises a CRT display screen, a centralprocessor, and a solid-state keyboard withsoftware-programmed functions. The CRTscreen is capable of displaying about 1,200flicker-free characters, and it may beoriented horizontally or vertically. The14-in. CRT is refreshed from local memoryat, normally, 40 frames/second. CPU wordsize is 16 bits, and memory size is 4kwords, expandable to 32k. Cycle time is2 microsec; direct addressing, 2k words,with indirect addressing at 32k single level.The CPU has 16 index registers (auto). I/Omaximum word rate is 500 kHz.

As a standard package, the IMLACPDS-1 comes with a text and graphicsediting program. A proprietary interactivegraphics pattern permits line drawinggraphics editing from the keyboard, as wellas limited text.

Information Technology, Inc.164 Wolfe RoadSunnyvale, California 94026

1TI-4900Basic price of the 4900 with 4k memory

and an ASR-33 is $12,450; it is $9,950without the Teletype. Memory cycle timeis 0.975/1.75 microsec and word length is16 bits. Memory size is 4k expandable to32k. The machine has eight accumulators,16 hardware registers, and 6 hardwareindex registers. Full-word add time is1.94/3.5 microsec; hardware multiply timeis 10 microsec and divide time is25 microsec. Maximum DMA word transferrate is 1 MHz. Various peripherals areavailable. Software includesFORTRAN IV.

Infotronics Corporation8500 Cameron RoadAustin, Texas 78753

mini/maxThe Infotronics mini/max computer is

an 8k machine, expandable to 65k, with 80basic instructions which allow 3,000discrete operations throughpseudoinstructions. The system has a2-microsec memory cycle time and canoperate up to eight disk controllers. Addtime is 3 microsec and multiply is8 microsec. The maximum I/O is 2,000kbytes/second. An expanded system of the16-bit machine can be purchased with 18levels of priority interrupts, a60-characters/second tape reader, aIIO-character/second tape punch, and a300-card/minute reader/printer. The basicunit sells for $16,500. The expandedsystem costs approximately $42,100.

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Software includes a real-time executive andan assembler.

Interdata2 Crescent PlaceOceanport, New Jersey 07757

Models 2, 3, and 4Interdata Models 2, 3, and 4 have a

number of similar characteristics. Thecommon features include 16-bit halfwordmemory, addressable and alterable to an8-bit byte level, 16 general registers, anddirect addressing of up to 256 devices.Software packages include I/O system,editor, and debugging; FORTRAN, micro,and 1, 2, or 3 pass assemblersare availablefor Models3 and 4.

All three processors include 16general-purpose user registers. These act asindex registers or accumulators to permitthe programmer to keep track of numerousloops and real-time combinations withouthaving to retrieve them from memory. InModels 2 and 3 the registers residephysically in core, but can be manipulatedas if they were hardware functions. InModel 4, these registersare implemented inhardware. The ROM is a high-speed(4QO-nsec) nondestructive memory whichstores the microprogram used to interpretand execute the main program. The threemachines also have one external interrupt,expandable to eight, and 78 instructionswith two address modes.

Model 2 has the slowest speed, with amemory cycle time of 3 microsec and anadd time of 45 microsec. Read/write datatransfer rate is 5 kbytes/second. Nohardware multiply/divide, floating point,hardware block transfer, or high-speedmemory access options are available forModel 2. They can be obtained withModels 3 or 4. Model 2 was listed at$6,600, but introduction of the newModell has dated the machine.

Model 3 has a 1.8-microsec cycle timeand a 34-microsec add time. Read/writedata transfer rate is 6 kbytes/second anddirect-memory-access rate is750 kbytes/second. Word length is 16 bits,and the 4k memory is expandable to 64k.Model 3 is priced at $8,900.

Model 4 has a 1.0-microsec cycle timewith 4k-64k memory. Add time is3.2 microsec; read/write data transfer rateis 25 kbytes/second and direct memoryaccess rate is 900 kbytes/second. The basiccost of Model 4 is $12,300. An ASR-33 ispriced at $1,900 for all Interdata systems.All three machines noted were firstdelivered over 2 years ago.

ModellThe Interdata Modell is a new (1970),

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physically small machine (5)4 in. high x17~ in. wide x 17 in. deep, weighing451bs) priced at $4,650, with 2k memory.The basic 2k is expandable to 16,384 8-bitwords. The machine has a 1.00microseccycle time and 3-microsec add time. Thereare seven internal registers and 47instructions. Addressing modes are direct,indirect, and auto-indexing. Read-onlymemory is available in modules of 2,048words. Four hardware interrupt levels arestandard and expandable to eight.Maximum number of I/O devices: 256.Read/write block transfer rate is 400,000bytes/second; selector channel rate is500,000 bytes/second. Power failprotection is optional but a real-time clockis standard. Software includes assembler,monitor, and simulator.

Model SThe ModelS is Interdata's largest

computer. The basic memory of 8k bytes isexpandable to 64k bytes, with 64k bytesof directly addressable memory. Word sizeis 16 bits; data word length is 8, 16, 32 bits(parity option). Memory cycle time is1.0 microsec of core memory and 400 nsecof read-only memory. The machine has 16hardware registers (IAbits each) and eightfloating-point registers, each 32 bits long.Fifteen general registers may be used forindexing. There are 113 standardinstructions, including floating point andprivileged instructions. Typical times:16-bit load halfword, 2.8 microsec; 16-bitadd halfword, 3.2 microsec. Typicalmicroinstruction execution time is400 nsec; 16-bit micro add time is0.800 microsec. I/O program transfer rateis 30 kbytes/second; firmware 1/0 is thesame. Priority interrupts: up to 256 levelswith automatic queuing. There are 16hardware priorities, expandable in groupsof 16. Software includes an assembler,basic OS, real-time OS, and FORTRAN IV.

The unit in a standard cabinet weighs175 lbs and measures 66 in. high x 22\02 in.wide x 30 in. deep. Basic price with 8k is$15,600.

IRA Systems, Inc. 332 Second AvenueWaltham,Massachusetts02154

SP-6SThe SP-65 sells for $14,900 with 4k

basic memory expandable to 64k. Wordlength is 16 bits and cycle time is1.8 microsec. The computer has 200hardware instructions, 30 data channels,and 10 basic priority interrupts with 30maximum. Standard I/O devices areavailable.

Lockheed Electronics Company

Data Products Division6201 East Randolph StreetLos Angeles, California 90022

MAC-16The basic MAC-16 contains six 16-bit

registers plus a full adder and is suppliedwith a 4,096~ore memory, expandable to65k with add-on units. Memory cycle timeis 1 microsec, hardware multiply time is9 microsec, and divide time is 12 microsec.Add time for a full word is 2.0 microsec.Maximum DMA word transfer rate is800kHz.

Four nested interrupt levels in the basicmachine are expandable to 64 levels,allowing up to 64 programs to be queuedfor execution in real time.

Standard software includes theLockheed Electronics Assemble Program(LEAP) symbolic assembler, programloader, debug and editor programs, mathlibrary, I/O driver, and diagnostics. TheLEAP assembler and MAC-16 simulator areavailable in program-coded FORTRAN IV.The basic computer with ASR-33 Teletypewas originally priced at $11,950. With 8kwords, the price increased to $15,900.

The MAC-16 has recently been upgradedby the addition of previously optional CPUand memory features. The new standardMAC includes a DMA channel, eighthardware interrupts, memory expansionadaptor, power fail and restart protection,and a 60~ycle real-time clock. The price isnow listed at $11,200 for a CPU with 4kmemory and the above features.

MAC Jr.The MAC Jr. is a new model (first

shipped to customers in 1970) that iscompatible with the MAC-16. The smallermachine has a l-rnicrosec cycle time, 16-bitword, and a standard 4k memoryexpandable to 8k. Add time is 2 microsecand the machine has 72 instructions. Fourstandard priority interrupts are included,expandable to 16, with automatic storeand restore. Interface and controllers areidentical for both MAC computers. Theprice of the MAC Jr. is $7,900, includingCPU with 4k memory and power supply.

MicroSystems644 East Young StreetSanta Ana, California 92705

Micro800The Micro series computers utilize

microprogramming techniques. TheMicro 800 features a I.I-microsecfull-cycle core memory with amicrocommand execution time of220 nsec. Add time is 1.22 microsec andmaximum word transfer rate is 910 kHz(8-bit). Core memory is 4k, expandable to

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

32,768 bytes (8, 9, or 10 bits) in4,096-byte increments. Read-only storage(ROS) uses discrete diodes in printedcircuit board modulesof 256 16-bit words.File registers are a set of 16general-purpose 8-bit registers. Themachine has 15 basic instructions and oneaddress mode. A direct-memory-access(DMA) channel has a maximum transferrate of 909,000 bytes/second. AP800 is anassembly program for generating theread-only storage diode maps; it is writtenin FORTRAN IV. A simulator, which runsOn the Micro810, provides for interactivesimulation of firmware programs.

The basic system consists of a centralprocessor containing 16 multipurposeregisters, 256 words of read-only memory,console, and power supply to function as amicroprogrammed controller. Price is$3,200. The basic cabinet measures 8-)<\ in.high x 17-3/5 in. wide x 23 in. deep; fullyexpanded, it weighs 75 lbs.

Micro810The Micro 810 is a microprogrammed

adaptation of the 800 system with core.The microprogram (firmware) converts thebasic 800 machine into asoftware-programmable macrolevelgeneral-purpose computer. The unitcontains 16-bit registers, variable precisionoperations, and 89 instructions, includingmultiply and divide with eight addressmodes. Maximum word transfer rate is910 kHz (8-bit). Memory cycle time is1.1 microsec and full-word add time is10 microsec (16-bit). The basic Micro810price of $6,900 comprises a Micro800system with 768 words of read-only store,a 4,096-word x 8-bit core memory, and aTeletype interface. The ASR-33 is $1,200for all Micro models.

Micro812The Micro812 can operate as a data

concentrator, a preprocessor fortime-sharing and information systemnetworks, and as an interactive processingsystem of its own. Microprogrammedhardware receives serial data from up to 32low-speed input lines, with multipleformats and mixed baud rates, andassembles the information into charactersfor entry into a circulating buffer withinthe processor's core memory. The 105general-purpose and communications­oriented instructions include ASCII paritygeneration, cyclic code generation, andcharacter search. As a datacommunications processor, the 812accommodates four signaling rates to300 baud.

The basic Micro812 consists of themicroprogrammed processor, powersupply, 4,096 x 8-bit core memory

Behav. Res. Meth' & Instru., 1970, Vol. 2 (6)

( 1.1-microsec cycle time), power-failinterrupt, automatic restart, and real-timeclock at a cost of approximately $10,850.Up to 16,384 bytes of core memory andfive communications and peripheralinterface option boards can be added. Anexpansion chassis accommodates anadditional 16k bytes of core memory andeight interface option boards.Supplemental magnetic storage can besupplied up to 256 kbytes.

Mini-Comp, Inc.2 Mercer RoadNatick, Massachusetts 01760

MC 232 Time-Sharing SY~1em

The MC 232 is a small computer systemdesigned purely for time sharing. A basic16k-word system supposedly can supportup to 32 simultaneous users working froma variety of terminals, including Teletypes,typewriters, and CRT displays. The corememory is expandable from 12k to 32kl o-bit words.

The system has a provision for using aterminal as a desk calculator, an addingmachine, or as a programmable calculator.Any seven terminals can be in theprogramming mode simultaneously. So theother 25 would have to be used as simplede sk calculators. Terminals may behard-wired up to 2,000 ft from themachine or used over conventionalcommunication lines.

The Mini-Comp MC 232 operates inboth fixed and floating decimal modeswith 12-place accuracy. Programs arelimited to only 250 instructions with theminimum system. Mini-Tok, a calculatorsystem language, and Basic are available assoftware.

The basic 16k MC 232 system costs$45,000 with eight Teletype units.

ModularComputer Systems, Inc.2709 North Dixie HighwayFort Lauderdale, Florida 33308

Modcomp-l l and -111The Modcomp-I1 and -l l l are recent

entries into the minicomputer market.Both machines have the followingcharacteristics: 16-bit word length, basic4k memory, .80-microsec memory cycletime, 1.6-microsec add time, and7.2-microsec multiply. Software includesmacro and basic assemblers andFORTRAN IV.

The 4k memory of the Modcornp-l l isexpandable to 16k. The machine has 164instructions with direct addressing and sixother modes, 0-8 priority interrupts, and16 DMA channels. Maximum I/O is 400

kbytes/second. Price of the basic unit is$9,800.

The Modcomp-lll is priced at $13,500for the 4k version and is expandable to32k. The computer has 182 instructions, ato 32 priority interrupts, and 16 DMAchannels. Maximum I/O is 1,660kbytes/second,

Monitor Data Corporation17805 Sky Park CircleIrvine,California92664

MD-708The basic 4k system of the recently

introduced MD-708 is priced at $3,750.The Ik system sells for $3,250. Theminicomputer is an 8-bit, Lo-microsecgeneral-purpose machine with 1,024 words,expandable to 65k. Add time is1.6 microsec. Memory is directlyaddressable up to 4k words; direct memoryaccess is available as an option. Basicrepertoire is 117 instructions (101standard). Number of priority interrupts: 1to 8. Hardware registers: 8.

Motorola Instrumentationand Control, Inc.

P.O. Box 5409Phoenix, Arizona 85010

MDP-IOOOMemory cycle time for the MDP-IOOO is

2.16 microsec, word length is 8 bits, andthe 4k memory is expandable to 16k.Full-word add time is 4.32 microsec.Maximum DMA word transfer rate is430 kHz. The machine has fiveprogrammable hardware registers of 12-bitlength, all of which can be used asaccumulators. Three of the five are usableas index registers. Number of instructions:50. Number of priority interrupts: 0 to 64.

A standard feature is the relative-timeclock, which, at programmed timeintervals, generates an interrupt request.Acknowledgment of the interrupt causesthe program to be branched automaticallyto the portion associated with the real-timerequest. Software includesa conversationalassembly system, monitor package, 1/0drivers,and debug.

Basic unit price was listed atapproximately $8,000, without an ASR-33Teletype. The newest(March 1970) listing,with 4k memory, is $6,900. The machinehas been on the market about 3 years.Dimensions of the 8k enclosure arc7lh x 19 x 21 in. The weight of the 8k unitis 30 lbs,

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Multidata, Inc.7300 Bolsa AvenueWestminster, California 92683

Multidata Model AThe Multidata minicomputer was first

delivered to customers this year. TheModel A basic configuration includes 4,09616-bit words of core memory in tandemwith 32,768 words of disk memory, amemory-access controller, a centralprocessor, an input/output bus, and ateletypewriter (ASR-33). Thememory-access controller enables thecentral processor to execute programsapproaching 32,768 words in length from a4,096-word core. A larger core is necessaryonly if the time-critical portion of aprogram, which must be resident, will notfit into the basic module. The controllerdivides core memory into 256-word pagesand transfers program segments a page at atime from disk into core. Any programsegment may go into any page, whichmeans that continuous program segmentsmay be scattered in core. A memory map(a complement of 20-nsec registers in thecontroller) keeps track of the page assignedto each program segment.

The core memory of 4,096 words isexpandable to 65,536 words. Disk memoryof 32,768 words is expandable to 131,072.The system has eight programmableregisters, up to 256 nested interrupts, and abasic complement of 125 instructions.Model A software is based on a32,768-word memory rather than 4,096words. Software includes a monitor whichmaintains system programs in core onlywhile they are active, the FORTRAN IVcompiler, a two-pass macroassembler, andutility programs. Price of the basic 4ksystem with Teletype and disk is $14,995.

Philco-Ford CorporationWestern Development Laboratories3939 Fabian WayPalo Alto, California 94303

Models 1216 and 1220·FThe 1216 and 1220-F computers are

alike in the following characteristics: 4k-bitminim urn mem ory size, eightpriority-interrupt levels, eight directmemory channels, and 121 hardwareinstructions. The 1216 is expandable to6Sk, with 16-bit word size and3.4-mierosec eycle time. The 122O-F has a20-bit word size and 2.0-microsec cycletime. Both machines use FORTRAN andhave a full line of peripherals. Model 1216,however, is no longer being marketed as astand-alone component due to areorientation of marketing approach.

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Quantel Corporation3474 Investment BoulevardHayward, California 94545

QuantelThe .Quantel computer offers 40

instructions, including arithmetic (decimaland binary), logicals, branching, testing,editing, and I/O with indirect addressing.Microcommands may be taken from mainmemory. Because of the read-only memorytechnology, a specified instructioncomplement can be installed in mainmemory. The machine has 3.5-microseccycle time, and is field-expandable from4,096 8-bit words to 8,192 8-bit words in4,096 modules. Control includesl-microsec MOS ROM, with 1,024 wordsstandard. The standard unit allows theread-only type of control to originate frommain memory; however, no representativetiming is available for instructions run inthis manner. Single unit price for the basicsystem is $6,400.

Raytheon2700 South Fairview StreetSanta Ana, California 92704

Model 703With 4k memory and 16-bit word

length, the Raytheon Model 703 has a1.75-microsec cycle time, a 3.50-microsecadd time, and a 12.25-microsec multiply.The machine has 73 instructions, withaddressing direct and indexed; there arefour addressable registers, one hardwareindex. The basic system has one externalinterrupt; a maximum of 16 is availablewith six DMA channels. Maximum I/O rateis 1,150 kbytes/second. With as many assix active devices in the DMA channel, datarates of 571,285 16-bit words/second canbe accommodated. Software includes atwo-pass assembler, FORTRAN IV, and asimulator. The basic 4k unit is priced at$12,750. Each additional 4k up to themaximum of 32k is $6,500. The machine isavailable for $29,500 with 16k corememory and an ASR-33. First deliveries ofthe Model 703 were made 3 years ago.About 300 machines are in use.

Model 706The Raytheon Model706 was

introduced early in 1969 as a 16-bit 4kcomputer with a maximum memory size of32k. Price: $19,000.

Add time of the 706 is 1.8 microsec andmultiply is 6.3 microscc. Full cycle time of900 nsec permits data acquisition at byterates up to 2.2 MHz and a full, automaticpriority-interrupt response time of2.7 microsec. The priority-interrupt system

can be expanded to 16 levels. The standardI/O bus is used for programmed transfers atword rates up to 278 kHz. An optionalsix-channel DMA can be provided forapplications involving word rates up to1.1 MHz. The machine has 73 instructions.Software is the same as that noted for theModel 703. The main frame is 5~ in. highx 19 in. wide x 25.5 in. deep and weighs155 Ibs. An ASR-33 teletypewriter isincluded in the basic price.

Model 704Raytheon's 704 minicomputer was

introduced in 1969 as a 16-bit 1.5-microsecunit with 4k memory expandable to 16k.In 1970, the company announced animprovement in speed and memorycapacity. The 704 is now available with1.0-microsec cycle time and a 4k memory,expandable to 32k. Add time is2.0 microsec and multiply is 7.0 microsec.The basic configuration sells for $9,750and includes page size of 2,048 words, 74instructions, word and byte manipulation,a real-time priority interrupt (maximumnumber of interrupts, 16), direct I/O toCPU, four addressable hardware registers,and one hardware index register. The AIDin terface provides plug-in modularinterface ability. Options include areal-time clock, hardware multiply/divide,and high-speed direct memory access. AnASR-33 is not included in the basic price.The machine is compatible with 703/706software, providing over 400 programs andsubroutines including over 40combinations of monitors and executives.Weight of the 704 is 75 Ibs. Thedimensions are 15·% in. high x 17~ in. widex 23\-2 in. deep.

In the spring of 1970 Raytheonannounced a 33% cut in all conversionequipment including the 12-bit multiplexA/D converter which, in the 32-channelconfiguration, was marked down from$3,640 to $2,300.

Redcor Corporation7800 Deering AvenueCanoga Park, California 91304

RC-70The Redcor 70 is a modified version of

the Decade 70 designed for dataacquisition and control. The basic 4kmemory is expandable to 32k with 16-bitword length. Memory cycle time is1.9 microsec, add time is 1.9 microsec, andmultiply is 6.2 microscc. The machine hasnine hardware registers and 35 basicinstructions, four address modes. Numberof priority interrupts: 0 to 32; DMAchannels: 0 to 4. Maximum transfer rate is

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

1 MHz. Software includes a one-passassembler and FORTRANIV. Price of thestripped down 4k basic system is $12,900;an ASR-33 is $1,800. Additional 4kmemory is priced at $6,000.

Redcor Corporation is marketing a largercomputer system, the RC-77, whichutilizes RC-70 small computers asprocessing elements within the system.These are under the control of a softwaresystem incorporating a real-time and abatch-processing monitor. The concept ofincorporating two processors into thesystem provides complete backup. TheRC-77 has a 20k memory, expandable to65k, and a million-word disk memory at$111,000.

Rolm Corporation10300 North Tantau AvenueCupertino, California95014

Rolm-1601The ROLM is a ruggedized version of the

Data General Corporation Nova computer,built to withstand severe environments. A4,096 16-bit word model with Teletype,data channel, priority interrupt andpower-failure protect, and autorestart costsless than $20,000.

Scientific Control Corporation1215 West Crosby RoadP.O. Box 96Carrollton, Texas 75006

Model4700The 4700 has a 4k basic memory,

O.92-microsec cycle time, 16-bit word size,16-bit hardware index register, 16-bithardware accumulator, and two priorityinterrupts (console and I/O channel).Number of maximum external interrupts is256. Add time is 1.9 microsec. DMA wordtransfer rate is 1.1 MHz. The basic packagealso includes a multiplexer I/O channel,maximum of 64 devices, and an ASR-33for about $20,000. A microprogrammedinstruction repertoire provides theinstruction set. All software packagesexcept FORTRAN IV and the real-timemonitor run in the basic 4k memoryconfiguration. Software packages include amacroassembler, debug packages, I/Oexecutive, basic FORTRAN system,diagnostics, FORTRAN IV, and thereal-timemonitor.

Memory can be expanded from 4k to65,536 words, and up to 16 externalpriority-interrupt levels are available asoptions. The wide range of systemconfigurations can run as high as $200,000.The machine is about 2 years told.

Behav.Res. Meth. & Instru., 1970, Vol. 2 (6)

SpirasSystems332 Second AvenueWaltham,Massachusetts 20154

Spiras 6SThe basic Spiras 65 has a 4k-word (16

bits long) core memory, expandable to65k. The company also offers a read-onlymemory (ROM) with 512 words in thebasic machine (to 1,024 words), which isused for microprogramming with 32-bitword lengths.

Cycle time is 1.8 microsec and add timeis 3.6 microsec. The machine has 125instructions. Hardware includesfloating-point arithmetic, direct memoryaccess, multilevel interrupts, and a partyline input/output. Number of CPU I/Ochannels: 63 devices. The software includesa symbolic macroassembler,FORTRAN IV, IBM 360 simulator, andconversational basic. Average systempurchase price has been about $14,500,although the minimum configuration hasbeen listed at less.

Systems Engineering Laboratories690 I West Sunrise BoulevardFt. Lauderdale, Florida 33304

SEL 810A, 810B, and Systems 82The SEL 810A and Bare 16-bit

machines offering 4k words of memory,expandable to 32k. The A model is slowerthan the B (1.75 microsec as against0.75 microsec) and has fewer capabilities.The same peripherals and software can beutilized on both machines.

With the 81OA, add time for a full wordis 3.5 microsec, hardware multiply time is7 microsec, divide time is 10.5 microsec.Maximum word transfer rate is 572 kHz.The A model features two priorityinterrupt levels, pre- and postindexing,double-length accumulator, and multilevelindirect addressing in the basic unit, pricedat approximately $18,000 with ASR-33.There are 57 instructions, and addressingispartial direct. With 8k memory, themachine is priced at about $23,000.Maximum DMA transfer rate is 572 kHz;maximum available number of individuallyarmable priority interrupts is 96. The 810Ahas a two-pass assembler,a macroassemblercapability, and it uses a FORTRAN IVcompiler.

The SEL 810B has a second hardwareindex register and a real-time monitor forforeground and background handling inaddition to the features of the 81OA. Addtime is 1.58 microsec, multiply time is4.74microsec, and divide time is6.32 microsec, including access andindexing. Maximum word transfer rate is

1.33 MHz. Price is about $30,000 withASR-33.

Systems 82 is new (late 1970) withl o-bit, 4-16k words of core, and 9OO-nseccycle time.TEe, Inc.6700 South Washington AvenueEden Prairie, Minnesota 55343

ModelS20-PCPThe 520-PCP is a 16-bit-word-Iength

computer with a 4k memory, expandableto 16k, selling at $9,900 for the basicpackage. Memory cycle time is1.0 microsec and add time is 2.0 microsec.Maximum I/O is 2,000 kbytes/second, andthe machine has 61 instructions with directaddressing. There are 12 priority interruptswith 0 to 10 DMA channels. Softwareincludes a two-passexternal assembler. Therack is approximately 56 in. high.

Tempo Computers, Inc.1550 South State College BoulevardAnaheim, California 92806

TEMPO-lFor a basic price of $15,600, the Tempo

system includes a 4k memory, 9OO-nseccycle time, 14 hardware registers (8general-purpose), register-to-registeroperation, four hardware priorityinterrupts, 14 addressingmodes, more than100 hardware instructions, an ASR-33Teletype, and software packages,includingUSA Standard FORTRAN IV and amacroassembler. Word size is 16 bits. Addtime is 1.8 microsec, and maximum wordtransfer rate is 1.33 MHz. The machine isavailable in a console or in a 6Q-in. rackwith room for 12 or more peripheralcontrollers.

Options include: memory growth to65k, parity, up to 25 hardware registers,multiprogram feature, program flags,additional interrupts, and others. TheTempo-I has been available since 1969.

Texas Instruments, Inc.12203 Southwest FreewayStafford, Texas 77006

TI-960Using plug-in printed circuit cards, the

960 process-control computer can interfacewith a wide variety of devices. As many as4,096 I/O lines can be handled and eachline can be addressed in groups of 16 orindependently. The machine is expandableto 65k words (16-bit word size) from theminimum 4k of memory capacity. Memorycycle time is 1.0 microsec, and add time is6 microsec. Instructions: 57. The 960

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software package includes a processautomation monitor. The 4k version of the960 is priced beginning at $14,500.

TI-980The TI-9S0 is a general-purpose

stored-program digital computer with a16-bit word, l-rnicrosec memory cycletime, and 400-nsec memory access time.Add time is 2 microsec; multiply time is6.5 microsec. Basicmemory is 4,096 wordsexpandable to 65,536. The machine haseight 16-bit registers and 85 instructions,including multiply and divide. There arethree priority interrupts: internal, DMAP,and I/O bus. Software includes a real-timemonitor, a symoblic assembly programimplemented for the 980 and IBMSystem/360 computers, FORTRAN IV, alink editor, and others. Basic price of theunit with 4k memory is $16,700.

Unicorn, Inc.1275 Bloomfield AvenueFairfield, New Jersey 07006

CP-8Aand CP-8DUnicorn is marketing a family of new

small computers which can operate asperipheral device controllers, dataconcentrators, or mass storage devices. Thesmallest is the CP-SA, a machine with 5128-bit bytes of read-only memory (ROM),four hard-wired scratch-pad registers, and40 byte-oriented instructions. The CP-8Aispriced at $1,800.

For mass storage, the CP-8D has amagnetic tape cassette system that storesup to one million bytes per cassette. Thiscomputer also has lk bytes of ROM,high-speed search, four priority interrupts,and an index register. Cost: $4,900.

Read-write memory is 1,024 to 32kbytes; memory cycle time for the CP seriesis 1.75 microsec. Read-only memory is 512to 32k bytes; cycle time is 350 nsec. Addtime is 3.5 microsec. Addressing is directand indirect, with 50 instructions.

UniComp, Inc.18758 Bryant StreetNorthridge, California 91324

Comp-Io and Comp-18Built especially for use in a rugged

environment, the Comp-16 includes a0.9-microsec full memory cycle time, a2.2-microsec add time, and a core diodememory expandable from the basic 4k to65k (16 bits). The computer has sixmemory index registers, simple commandstructure, parallel I/O bussing, octalreadout on the front panel, and DMAinterface. Available software includes

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Basic, conversational FORTRAN, arelocatable assembler, multiple precisionfloating-point routines, and specialreal-time packages. ROM and/orscratch-pad memory is optional. Basic unit,with 4,096 words and DMA,is slightly lessthan $10,000.

The Comp-l S costs about $700 moreand has a maximum memory size of 262k.Both machines were first delivered thisyear.

Varian Data Machines2722 MichelsonDriveIrvine, California 92664

S20/iThe Varian 520/i features a dual

environment (a dual set of programcounter, index register, and accumulatorregisters in the central processor) withinwhich the computer can operateinterchangeably. When the interruptoccurs, the program can switch to theregisters of the second environmentwithout any delay for saving the contentsof the registers of the first environment. Atthe end of the interrupt, the programreturns to the undisturbed data.

Memory cycle time is 1.5 microsec, withthe memory expandable from 4,096 bytes(8 bits) to 32,768 bytes, direct addressingto 4,096 bytes. Add time for a full word is4.5 microsec. Th~mm;;"achine has sevenaccumulators, seven hardware registers, andone hardware index register. The maximumnumber of external interrupts is 11.

The main frame is 8-% in. high, 19 in.wide, and 20 in. deep, with a weight of481bs. Basic cost of the 520!i systemequipped with 4,096 bytes of corememory, console, programmed parity lineI/O system, four priority interrupts, andpower supply is now listed as $6,000. Themachine had been listed at $7,500.

Recent software innovations have beenintegrated into a single Master OperatingSystem (MOS), which includes I/O control,system executive, system loader, a two-passassembler, FORTRAN IV, andmaintenance and debuggingpackages.

With 8k words, the price is $8,000; withASR-33 and controller, the total cost is$9,400. Adding a magnetic tape unitincreases the amount by $S,900. A diskmemory costs $7,200. The 520/i was firstdelivered in late 1968.

620/iThe Varian 620/i was designed for

on-line data systems and has magnetic corememory, word length of 16 or IS bits,1.8-microsec full cycle time, 700-nsecaccess time, and 4,096 words expandableto 32,768. Add and subtract time is

3.6 microsec, multiply is 18.0 microsec,and input/output from memory is5.4 microsec. The machine has ninehardware registers, over 100 basiccommands, six addressing modes, anddirect addressing to 2,048 or 32,768. Themaximum number of external interrupts is64. The 620/i was originally priced at$12,100, and the first machines weredelivered about 3 years ago. The basicsystem with 4,096 16-bit words of storagehas been reduced in price to $9,950.

The Varian 622/i is an IS-bit computer,with 4,096 18-bit words of storage, whichhas been reduced in price from $14,100to$11,995. The Varian R.Q20/i is merely amore rugged version of the 620/i and isdesigned for operation in severeenvironments.

620/fThe Varian 620/f is the latest of the line

and is listed at $13,000, with Bk words.The 4k version is priced at $10,005. AnASR·33 and controller increases the priceby $1,SOO. A complete 620/f system withmagnetic tape totals $23,700; the systemprice with disk is $24,700.

The basic memory cycle time of the620/f is 750 nsec. The machine can beequipped with an optional braided coreROM. Access time to the read-onlymemory is 300 nsec. Processing of ROMdata and programs requires 500 nsec permachine cycle. Word length is 16 bits, with4,096 words basic expandable to 32,768.Add or subtract time is 1.5 microsec,multiply (optional) is 3.1-7.0 microsec.Input/output times from A or B register is4.1 microsec; from memory it is4.9 microsec. There are 148 standardinstructions, 10 optional.

The 620/f is compatible with allprograms written for earlier models in theVarian 620 line. New programs writtenspecifically for the 620/f take advantage ofthe computer's expanded instruction set.

Up to 32 peripheral controllers can beconnected to the basic I/O bus. Theseinclude all standard input/output devices.The machine features three different 1/0operations: a basic I/O bus party linetransfers data rates up to 30,000characters/second; a direct memory accessmode interlaces program steps with I/O toand from memory to produce data rates upto 276,000 words/second; and a direct portto memory is provided by the prioritymemory access for high-speed transfer ratesup to 1.3 million words/second.

Varisystems Corporation257 Newton RoadPlainview, New York 11803

Behar, Res. Meth. & Instru., 1970, Vol. 2 (6)

PAC-I6/2The basic 4k (expandable to 8k) unit

costs $3,850 and includes 16-bit wordlength, 1.75-microsec memory cycle time,and 2.O-microsec add time. Maximum I/Ois 666 kbytes/second. The machine has 16instructions with direct addressing and 0 to2 priority interrupts. An assembler andFORTRAN IV are available as software.

Viatron Computer Systems CorporationRoute 62Bedford, Massachusetts 01730

Models 2140 and 2150The Viatron 2140 is a 4k machine with

two interrupt levels; the 2150 is a8,I92-word computer with four interrupts.Both have I6-bit word length and oneDMA channel. Memory cycle time is2.0 microsec; add time is 5 microsec. Themaximum I/O is 330 kbytes/second. Thereare 85 instructions. Software includes atwo-pass assembler and FORTRAN. Priceof the 2140 computer is $4,752. The 2150is under $10,000. Input/output equipmentoptions include teletypewriter, typewriter,card reader, CRT, magnetic tape, and magtape cassette.

Victor Comptometer Corporation3900 North Rockwell StreetChicago, Illinois 60618

820/10The Victor 820/10 has an average

monthly rental cost of $300 and averagepurchase price of $10,000; the basic unitprice, however, is $6,950. Memory cycletime is 2.0 microsec, access time is5 microsec, Word length is 64 bits, andmaximum memory capacity is 6,144 (core+ read-only instruction). The machine hasfour index registers, indirect addressing,but no automatic interrupt. There are fourCPU I/O channels.

820/30The 820/21, 820/25, and 820/30 are all

very similar, so the 820/30 will bedescribed here. Word length is 64 bits,access time is 5 microsec, and maximummemory capacity is 16,384. Minimumcapacity is 0.064 (core, data) and 1 (+ readonly). The 820/30 has five index registers,four CPU I/O channels, editinginstructions, indirect addressing, andbuffering, but no automatic interrupt.Basic machine cost is approximately$20,500; the average system purchase cost,however, is about $29,900, with a $900average monthly rental.

Behav. Res. Meth. & Instru., 1970, Vol. 2 (6)

WangLaboratories, Inc.836 North StreetTewksbury, Massachusetts 01876

WANG 3300 BASIC Time Sharing SystemWANG 3300 BASIC is a compact

computer system designed for use as anin-house multiterminal time-sharing systemutilizing the Basiclanguage.

Word length is 8 bits with 1.6-microsecmemory cycle time (add time,4.8 microsec) in 4k units up to 65k with256-byte pages. The machine has a72-instruction set with 21 memoryreference commands, a push-down/pop-upaddress scheme, and a direct-accesschannel.

The 3300 is set up with an 8-bitaccumulator, an 8-bit accumulatorextension, and an 8-bit addressable statusregister; it is claimed to use every byte ofcore as an index register.

The system can handle up to 16 userswith a mixture of Teletypes and I/Owriters. Remote access to the centralprocessor is limited to the Model 3315Teletype. Model 3310 I/O writers must belocated within 75 ft of the centralprocessor.

Minimum system configuration for theBASIC computer and two terminals is 12kof core. This is said to give each user a1,000-byte partition. Partition size isvariable and additional core storage (to65k) can be added.

Terminals may be standard 33-ASRTeletypes or I/O writers (IBM Selectrictypewriters) with magnetic tape cassettes.A low-cost 65,000 disk and 0.5 megabytedisk will be available.

Four available addressing modes includein page, absolute (page 0 on 1), immediate,and indirect. The primary language is Basic.Other software includes an assembler, asource tape editor, a debug package, loaderand lac S modules, and diagnosticroutines.

A two-user Teletype system includes a3300 central processor costing $4,950, a3301 memory at $5,000 (4k memory at$2,500), 3315 ASR-33 Teletypes, $3,500(at $1,750 each), and a 3316 control forfour at $500. Total price is $13,950,$6,975 per station.

For a four-user station the priceincreases to $19,950, or $4,987.50 perstation. The $6,000 added cost for thelarger system covers an extra 4k ofmemory ($2,500) to bring theconfiguration to 12k, and two additionalTeletypes ($3,500). There is an additionalcost of $1,500 for BASIC and systemsetup. But a 12k minimum core is requiredfor BASIC. The four-user I/O Writer

Cassette System is $24,150 plus the $1,500BASIC charge. Sixteen terminals withTeletypes and BASICis priced at $55,950;this includes 32k total bytes of memory,21.5k total bytes left for partition, andI ,344 bytes for each terminal.

Optional typical monthly maintenancecontract charges are $34.65 for the centralprocessor, $17.50 for 4k modules, $17.50for 33-ASR Teletype, and $14 for cassettedrives. The Wang Time-Sharing System isnew, 1970.

Westinghouse Electric CompanyHagan Computer DivisionBox 868Pittsburgh, Pennsylvania 15230

P-2000The Westinghouse P-2000 is a

16-bit-word machine with a minimumcapacity of 4k expandable to 65k. Memorycycle time is 0.5/3.0 microsec; add time is7 microsec. The unit has 32 basic hardwareinstructions, four direct-memory-accesschannels, and 128 direct data channels,with 64 buffered. Software includesFORTRAN IV and a two-pass assembler.Although the basic cost is about $11,000,the system becomes expensive as it isexpanded into useful form. And thehousing is not small; rack height is about87 in. Standard I/O devices are available.

Xerox Data Systems701 South Aviation BoulevardEI Segundo, California 90245

CE-16 and CF-16The CE-16 and CF-16 computers were

designed by Scientific Data Systemsengineers before the company became partof Xerox Data Systems. Both machineshave 16-bit word lengths and minimummemory capacities of 4k. The CE-16 isexpandable to 16k, the CF-16 to 32k.Memory cycle time for the CE model is8 microsec and add time is 16 microsec; forthe CF-16, cycle time is 2.7 microsec andadd is 5.3 rnicrosec. Both machines havethree priority-interrupt levels with 126hardware instructions, onedirect-memory-access channel, and sevenhardware registers. Software includesFORTRAN, loaders, debug, source tapepreparation, an assembler, and mathlibrary.

The Model CE-16 with 4k sells forapproximately $9,980; the CF-16 is pricedat $7,990. Rack height is approximately15 in.

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Other Small ComputersPhillips Business Systems, Inc. (100 East

42nd Street, New York, New York 10017)recently began making deliveries on amachine which is presentlybusiness-oriented, the P-350 computer,priced at $8,450 for 3.2k basic memory,expandable to 19.2k.

The Friden Division of Singer Company(2350 Washington Avenue, San Leandro,California 94577) has entered the marketwith System Ten, a 6-bitl Ok-expandable-to-l l Ok computer withhard-wired time sharing, priced at $15,900.

The Electronic Engineering Company ofCalifornia (P.O. Box 58, Santa Ana,California 92702) markets a real-timeengineering EECO-1600 computer with16-bit word size, 4k memory expandableto 32k, 2.6-microsec cycle time, numeroushardware registers, and 16priority-interrupt levels. Basic price:$7,600.

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Computer Signal Processors, Inc. (209Middlesex Turnpike, Burlington,Massachusetts 01803) recently introducedthe CSP-30 computer with a 200-nsec addtime and l-microsec multiply. The machineoperates at 10 MHz to perform continuousreal-time fast Fourier transforms atsampling rates up to about 45 kHz.

The Wilkinson Computer Sciences 881(Box 350, Sweetwater Avenue, Bedford,Massachusetts 01730) is a 16-bit machinewith 2k memory expandable to 32k, pricedat $7,500. Cycle time is 2.0 microsec.

REFERENCESHABER, R. N. An on-line computer in a visual

perception laboratory. Behavior ResearchMethods & Instrumentation, 1968, I, 86-93.

HUESMANN, L. R. Controlling experiments with

a general-purpose time-sharing system.Behavior Research Methods &Instrumentation, 1969, 1,276-280.

MAYZNER, M. S. The research potential of acomputer-based cathode-ray tube displaysystem. Behavior Research Methods &Instrumentation, 1968, I, 41-44.

MOISE, S. L., Jr., & JARRARD, L. E. Acomputer-controlled system for training andtesting primates. Behavior Research Methods &Instrumentation, 1969, 1,234-236.

OLLlVlER, R. T. A technique for selecting smallcomputers. Datamation, 1970 (January), 16,141-145.

RESTLE, F., & BROWN, T. V. A computerrunning several psychological laboratories.Behavior Research Methods &Instrumentation, 1969, 1, 312-317.

STADLER, S. J. On the varieties of computerexperience. Behavior Research Methods &Instrumentation, 1969, 1,267-269.

VITAL, W. R. Real time computers: Techniqueand applications in the psychological sciences.New York: Harper & Row, 1968.

NOTE1. Noted by N. S. Zimbel of Arthur D. Little,

Inc.

Behav. Res. !'vieth. & Instru., 1970, Vol. 2 (6)