CADCAM HARDWARE

The computing system in operation can be compared to a human being in terms of its operating characteristics.

The heart of any computing system is the central processing unit (CPU)

All necessary functions of a computer is carried out by the CPU

Main functions performed by the CPU are the arithmetic and logic function

CPU communicated with external world through its input device by giving data or to to control the computer

The output device is the means through which the CPU gives the results of the computation

Is the nerve centre of the computer Base on the software, it organises the

information processing for any given application

CPU in main frames and mini computers is essentially a printed circuit board(PCB) consisting a number of chips.

First microprocessor in late 60’s and early 70’s – general purpose microprocessor – INTEL 4004 used in a Japanese calculator released in 1971

INTEL 4004 – 4 bit microprocesser INTEL 8008 – 8 bit microprocessor now 64 bit Bit – length of words used by the

microprocessor to process information

Speed at which the microprocessor operate – system clock

The faster the system clock the faster is the execution of the instruction eg. 1 MHz- 3 Ghz

Evaluation of performance not only processor performance but also other peripherals and bench mark by SPEC (Standard Performance Evaluation Corporation.

For a CADCAM application, the computational load is very high – using of core processor

The requirement of a typical cadcam computer is at least 32 bits and preferably 64 bit microprocesser with a clock rate of above 1.0 GHz and address of at least 24 -32 bits

RISC – Reduced Instruction Set Computing has a small range of instructions present hence chip design is more efficient, faster and powerful

Memory unit – another important unit of a computer- where necessary data and program is stored

Integral part of computer to store data and programs

Semiconductor memory locations are organised in as a series of on/off switches(transistors)

Single chip is capable of storing 256 M- bit of information

ROM – Read only memory PROM – Programmable ROM RAM – Random Access Memory EPROM – Erasable programmable ROM EEPROM – Electrically erasable

programmable ROM Flash memory

Essentially read and write memory Information stored only during power supply

stays and hence power supply must always be on position – used of lithium battery

Two types of RAM - static and dynamic Static RAM – information is to be written

only once Dynamic RAM (DRAM) - information to be

continuously refreshed

Fast Page Mode(FPM DRAM) Extended Data Output (EDO RAM) Synchronous DRAM Rambus Direct Ram (RDRAM) Double Data Rate SDRAM – DDR-SDRAM

Devices use for communicating with computer

1.Keyboard2.Mouse3.Light Pen4. Joystick5.Digitizer6.Tablet

Resembles a fountain pen and works on a principle of light

To detect present of light on the screen The resolution of light pen is poor Used in refreshed type display devices

Widely used by designer Converting a physical location into

coordinate values Work area correspond to full CRT screen

Displayed designed work and simulation

1.Cathode Ray Tube (CRT)2.Plasma Panel Display3.Liquid Crystal Display

Once output is finalized on the display device, it can transformed to a hard copy

1.Graphical printer2.Plotters3.Photographic Devices

Fastest way of getting graphical output at low price.

Impact Dot Matrix Printer Thermal Transfer Ink Jet Printer Laser Printer Colour Copiers

Widely accepted output device for final output

Wide range of plotters of varying sizes - A0, A1, A2,A3, A4

1.Pen Plotters – flat bed and drum type2.Electrostatic Plotters3.Photographic Devices

Large amount of space required for storage purposes

1.Floppy disk2.Winchester Disk3.Magnetic tape4.Compact disk ROMs5.DVD

Software determines the way the computer is to be used.

Better software make for better utilization of the computer

Operating system form part of the hardware provide the use of all the hardware elements

Windows 95, Windows NT, UNIX, LINUX Editor – creating and modyfying disc file Linker – linking the object modules Debugger -used in program development to

identify logic and runtime errors.

Program laguages are basically translators and classified as interpreters and compilers

BASICS, FORTRAN for scientific community, PASCAL and C for CADCAM program development. LISP and PROLOG are also related to ACDCAM programming

THANK YOU