Digital Electronics Digital Electronics and File Managementand File Management

Unit DUnit D

ObjectivesObjectives

Introduce Digital Data Introduce Digital Data RepresentationRepresentationIntroduce Integrated CircuitsIntroduce Integrated CircuitsExplore Microprocessor Explore Microprocessor Performance FactorsPerformance FactorsUnderstand Computer Memory: Understand Computer Memory: RAMRAMExplore Computer MemoryExplore Computer Memory

ObjectivesObjectives

Introduce Computer File BasicsIntroduce Computer File Basics

Understand File LocationsUnderstand File Locations

Explore File ManagementExplore File Management

Understand Logical File StorageUnderstand Logical File Storage

Use FilesUse Files

Understand Physical File StorageUnderstand Physical File Storage

Digital Data Representation Digital Data Representation

The form in which information The form in which information is conceived, manipulated is conceived, manipulated and recorded on a digital and recorded on a digital device.device.

Uses discrete Uses discrete digits/electronic signalsdigits/electronic signals- 1,0 (bits - binary digits)1,0 (bits - binary digits)- On/Off On/Off - Yes/NoYes/No

Byte = 8 bits = 1 character Byte = 8 bits = 1 character

Coding Systems Coding Systems

Depends on computer Depends on computer

ASCIIASCII (7 bits) (7 bits)

Extended ASCIIExtended ASCII (8 bits - (8 bits - current PCs)current PCs)

EBCIDICEBCIDIC (8 bits - older (8 bits - older IBM machines )IBM machines )

UnicodeUnicode (16 bits - good (16 bits - good for languages - future)for languages - future)

Quantifying Bytes and BitsQuantifying Bytes and Bits

Bit = b Bit = b

Nibble = Half of a byteNibble = Half of a byte

Byte = B Byte = B

Kilobyte (KB) (1024 bytes)Kilobyte (KB) (1024 bytes)

Megabyte (MB) (Million bytes)Megabyte (MB) (Million bytes)

Gigabyte (GB) (Billion bytes)Gigabyte (GB) (Billion bytes)

Terabyte (TB) (Trillion bytes)Terabyte (TB) (Trillion bytes)

Integrated Circuits Integrated Circuits

A super thin slice of semi–conducting A super thin slice of semi–conducting material packed with microscopic material packed with microscopic circuit elements such as wires, circuit elements such as wires,

transistors, capacitors, logic gates, transistors, capacitors, logic gates, and resistors. Bits are represented as and resistors. Bits are represented as

electrical pulses that travel over electrical pulses that travel over these circuits. these circuits.

Also called a chip, microchip Also called a chip, microchip and computer chip.and computer chip.

Integrated Circuit UsesIntegrated Circuit Uses

Microprocessors Microprocessors

MemoryMemory

Support circuitrySupport circuitry

Chip Chip

PackagePackage

Microprocessor Packages Microprocessor Packages

DIPs (dual in-line packages)DIPs (dual in-line packages)

DIMMs (dual in-line memory DIMMs (dual in-line memory modules)modules)

PGAs (Pin-grid arrays)PGAs (Pin-grid arrays)

SECs (single-edge contact SECs (single-edge contact cartridges)cartridges)

Microprocessor (Processor)Microprocessor (Processor)

Designed to process Designed to process instructions instructions

Largest chip on Largest chip on motherboard motherboard

Intel: world’s largest Intel: world’s largest chipmaker (Pentiums)chipmaker (Pentiums)

AMD: Cheaper chips AMD: Cheaper chips (Athlons)(Athlons)

Motherboard Motherboard

Main circuit board Main circuit board

Microprocessor ComponentsMicroprocessor Components

Microprocessor PerformanceMicroprocessor Performance

Speed: microprocessor clock set Speed: microprocessor clock set clock speed (MHz or GHz )clock speed (MHz or GHz )

World Size: number of bits the World Size: number of bits the microprocessor can manipulate microprocessor can manipulate at one time (32-bit or 64-bit)at one time (32-bit or 64-bit)

Cache: high speed memory Cache: high speed memory (kilobytes)(kilobytes)

Microprocessor PerformanceMicroprocessor Performance

Instruction Set Type: Instruction Set Type: – CISC (Complete instruction set computer)CISC (Complete instruction set computer)– RISC (Reduced instruction set computer)RISC (Reduced instruction set computer)

Processing Technique:Processing Technique:– Serial Serial – Pipelining Pipelining – ParallelParallel

Look at benchmark testing to Look at benchmark testing to comparecompare

Memory Types Memory Types

Random Access Memory Random Access Memory (RAM)(RAM)

Virtual Memory Virtual Memory

Read-Only Memory (ROM)Read-Only Memory (ROM)

CMOSCMOS

RAMRAM

Temporary (volatile) holding area for Temporary (volatile) holding area for data, application software and operating data, application software and operating system system Expensive chip set Expensive chip set CircuitryCircuitryLess storage than disk Less storage than disk Capacitors hold bits Capacitors hold bits Capacity measured in MB (64 - 512 MB)Capacity measured in MB (64 - 512 MB)Speed in nanoseconds Speed in nanoseconds

Random Access MemoryRandom Access Memory

RAM Types RAM Types

SDRAM SDRAM – Synchronous Dynamic RAMSynchronous Dynamic RAM– fast and cheap fast and cheap – DIMMS DIMMS

RDRAM RDRAM – Rambus Dynamic RAMRambus Dynamic RAM– faster and more expensive faster and more expensive – RIMMs AND SO-RIMMsRIMMs AND SO-RIMMs

Virtual Memory Virtual Memory

Disk based Disk based

Stores parts of programs and Stores parts of programs and data until they are needed by the data until they are needed by the processorprocessor

Works with RAM, but is slowerWorks with RAM, but is slower

ROMROM

Permanent on a chip from Permanent on a chip from manufacturermanufacturer

Holds computer start up routine, Holds computer start up routine, which are hard-wired instructionswhich are hard-wired instructions

PROM: programmable via “burning” PROM: programmable via “burning”

EPROM: erasable EPROM: erasable

ROM BIOS (basic input/output ROM BIOS (basic input/output system)system)

Read-Only MemoryRead-Only Memory

CMOSCMOS

Battery powered Battery powered More permanent than RAM; less More permanent than RAM; less permanent than ROM permanent than ROM Stores basic computer Stores basic computer configurationconfigurationMust be updated via CMOS setup Must be updated via CMOS setup program when configuration program when configuration changedchanged

Complementary Metal Oxide SemiconductorComplementary Metal Oxide Semiconductor

Computer File CharacteristicsComputer File Characteristics

A collection of data on a storage A collection of data on a storage medium medium

Filename conventions Filename conventions

Filename extensionFilename extension

.txt.txt.txt.txt .jpg.jpg.jpg.jpg .exe.exe.exe.exe .doc.doc.doc.doc

File Locations File Locations

Device drive letters A: C: D:Device drive letters A: C: D:

Directory Directory – Root Directory (C:\)Root Directory (C:\)– Subdirectory or folder (C:\Documents)Subdirectory or folder (C:\Documents)– File specification or Path File specification or Path – File size and dateFile size and date

Filename extensionFilename

Secondary folder

Primary folder

Drive letter

C:\Music\Reggae\Marley One Love.mp3 C:\Music\Reggae\Marley One Love.mp3

Deleting FilesDeleting Files

Move to Recycle Bin in Windows Move to Recycle Bin in Windows

UndeleteUndelete

Empty Bin Empty Bin

File Management File Management

Helps you organize your Helps you organize your computer files computer files

File/Save and File/Open File/Save and File/Open

Utilities like Windows Explorer or Utilities like Windows Explorer or MAC Finder MAC Finder – list, find, move, copy, delete, renamelist, find, move, copy, delete, rename

Save vs. Save AsSave vs. Save As

Logical File Storage Logical File Storage

Filing cabinet modelFiling cabinet model

Metaphor to help you Metaphor to help you visualize files on a visualize files on a storage device storage device

Windows ExplorerWindows Explorer

Folder hierarchyFolder hierarchy

Using Files Using Files

Start application (open Word)Start application (open Word)

Create file (type text)Create file (type text)

Save file (File/Save)Save file (File/Save)

Close file and application (File/Exit)Close file and application (File/Exit)

Open file again for editing (File/Open)Open file again for editing (File/Open)

Edit file Edit file

Save file Save file – File/SaveFile/Save– File/Save AsFile/Save As

Physical File Storage Physical File Storage

Storage medium formatted Storage medium formatted into tracks /sectors into tracks /sectors electronicallyelectronicallyFile system keeps track of File system keeps track of names and file locations.names and file locations.– Windows uses FAT32 OR Windows uses FAT32 OR

NTFSNTFS

Clusters: a group of Clusters: a group of sectors that speeds up sectors that speeds up storage and retrievalstorage and retrieval

Physical File Storage Physical File Storage

FAT (File Allocation Table) on FAT (File Allocation Table) on each disk keeps track of where each disk keeps track of where all files are and which clusters all files are and which clusters are empty. If damaged, you lose are empty. If damaged, you lose everything.everything.

Defragmentation Utility Defragmentation Utility rearranges files to be stored in rearranges files to be stored in contiguous clusters.contiguous clusters.

Tech talk: How a microprocessor Tech talk: How a microprocessor executes instructions executes instructions

Complex task broken down into a Complex task broken down into a series of simple steps or series of simple steps or instructions instructions

Instructions are in machine code Instructions are in machine code (0s and 1s) and consist of: (0s and 1s) and consist of: – Op code: Operation code like Add, Op code: Operation code like Add,

Compare, etcCompare, etc– Operand: data address for operationOperand: data address for operation

Tech talk: How a microprocessor Tech talk: How a microprocessor executes instructions executes instructions

Instruction Set is built into Instruction Set is built into processor processor

Instructional Cycle is the execution Instructional Cycle is the execution of a single instructionof a single instruction

Fetch InstructionInterpret Instruction

Execute Instruction

Increment Instruction Pointer

IssueIssue

Who Who invented invented

the the computer?computer?

Digital Electronics Digital Electronics and File Managementand File Management

EndEnd