Chapter 2 Turning Data into Something You Can Use © The McGraw-Hill Companies, Inc., 2000 Processing Hardware

Ch 2© The McGraw-Hill Companies, Inc., CCI Overview Data and program representation Processor, main memory, registers RAM capacity, word size, processor speed Microcomputer

Ch 2© The McGraw-Hill Companies, Inc., CCI Computers Programmed to learn and adapt High costs slowed initial adoption More than 15 billion microprocessors and microcontrollers in use at the turn of the century

Ch 2© The McGraw-Hill Companies, Inc., CCI Data and Program Representation Binary system Two common schemes –EBCDIC –ASCII New scheme –Unicode

Ch 2© The McGraw-Hill Companies, Inc., CCI The Parity Bit A parity bit is a check bit It is an extra bit attached to the end of a byte to check accuracy

Ch 2© The McGraw-Hill Companies, Inc., CCI Capacity Bit –0s and 1s Byte –8 bits Kilobyte –about 1000 bytes

Ch 2© The McGraw-Hill Companies, Inc., CCI Larger Capacity Megabyte –about one million bytes Gigabyte –about one billion bytes Terabyte – about a trillion bytes

Ch 2© The McGraw-Hill Companies, Inc., CCI Processor Information –manipulates data into useful information Knowledge –results in reasoned analysis and applications

Ch 2© The McGraw-Hill Companies, Inc., CCI Processors, Main Memory, and Registers Processor –control unit –arithmetic/logic unit (ALU)

Ch 2© The McGraw-Hill Companies, Inc., CCI Logical Operations Logical operations in the ALU are simple comparisons such as =,, =

Ch 2© The McGraw-Hill Companies, Inc., CCI Boards and Chips Circuit boards Chips of silicon Use aluminum or copper to conduct electronic messages Semiconductor

Ch 2© The McGraw-Hill Companies, Inc., CCI Specialized Systems Coprocessors – math –graphics

Ch 2© The McGraw-Hill Companies, Inc., CCI Future PC on a chip

Ch 2© The McGraw-Hill Companies, Inc., CCI CISC, RISC, MPP CISC (“sisk”) –complex instruction set, serially executed –most mainframes and PCs RISC (“risk”) –reduced instruction set, serially executed –cheaper and faster –shift some work to software

Ch 2© The McGraw-Hill Companies, Inc., CCI MPP Massively parallel processing (MPP) –spreads calculations over many computers or processors

Ch 2© The McGraw-Hill Companies, Inc., CCI Main Memory Primary storage –RAM (random access memory) holds data instructions processed data for output is volatile

Ch 2© The McGraw-Hill Companies, Inc., CCI Main Memory Facts Contents temporary Capacity varies according to installed amount of memory chips

Ch 2© The McGraw-Hill Companies, Inc., CCI Registers High speed circuitry areas –store data and provide work areas –dedicated by function addition register subtraction register storage register

Ch 2© The McGraw-Hill Companies, Inc., CCI Machine Cycle Compares a series of operations to perform a single program instruction During the instruction cycles, or I-cycles, –control unit fetches instructions from main memory –decodes or interprets instruction During execution cycle, or E-cycle, –executes and stores result

Ch 2© The McGraw-Hill Companies, Inc., CCI RAM Capacity, Word Size, Processor Speed RAM capacity –software determines capacity needed –older computers may not have enough –computer’s RAM capacity is limited by the capacity of the motherboard Measured in megabytes, gigabytes, and terabytes –PCs to servers to mainframes, based on programs and load capacity

Ch 2© The McGraw-Hill Companies, Inc., CCI Word Size Number of bits computer can hold in its registers –sent through local bus 32-bit –most 486 PCs 64-bit –common PCs in CISC format

Ch 2© The McGraw-Hill Companies, Inc., CCI Processing Speed System clock controls speed of operations Speeds measured in megahertz (MHz) are common Gigahertz (GHz) predicted in the near future MIPS and FLOPS not commonly used

Ch 2© The McGraw-Hill Companies, Inc., CCI Focus on PC Purchasing –System unit Hard drive Floppy drive (except iMac) Power supply Motherboard Microprocessor Ram ROM Cache VRAM Ports Expansion boards Bus lines PC slots PC cards

Ch 2© The McGraw-Hill Companies, Inc., CCI Power Supply Power supply –protected by power surge protector or uninterrupted power supply unit (UPS) –voltage capacity can affect the ability to support internal parts

Ch 2© The McGraw-Hill Companies, Inc., CCI Motherboard Also called system board Includes CPU, memory chips (RAM, ROM), ports, coprocessors if not integrated on CPU, expansion slots Some boards have integrated sound, controller cards, and graphics

Ch 2© The McGraw-Hill Companies, Inc., CCI Microprocessor Intel (PC) –X86 –Celeron –Pentium MMX –Pentium II/III AMD (PC) –K6-2 –K6-3 –Athlon

Ch 2© The McGraw-Hill Companies, Inc., CCI Other Microprocessors Motorola (Mac) –68000 –68020 –68040 –PowerPC 601 –PowerPC 604 –PowerPC 620 –PowerPC 750

Ch 2© The McGraw-Hill Companies, Inc., CCI Compatibility Most software is backward compatible with new chips The older the hardware, the less the likely that it will install easily and function completely in new systems

Ch 2© The McGraw-Hill Companies, Inc., CCI The Truth About RAM Generally, more is better –must match with motherboard and CPU capabilities Software vendors traditionally understate software (RAM) requirements for a smooth operation of their software

Ch 2© The McGraw-Hill Companies, Inc., CCI A Suggestion –A computer running Microsoft Office 97 should have a minimum 32MB RAM for smooth performance –Microsoft Office 2000 needs 64 to 128 MB RAM

Ch 2© The McGraw-Hill Companies, Inc., CCI ROM Chips Read-only memory (ROM) Also known as firmware Helps boot the system BIOS –Basic Input Output System

Ch 2© The McGraw-Hill Companies, Inc., CCI Other ROM PROM –programmable ROM EPROM –erasable programmable ROM EEPROM (flash) –electronically erasable programmable ROM –can be rewritten without special equipment

Ch 2© The McGraw-Hill Companies, Inc., CCI Other Forms of Memory Cache memory (“cash”) –quick access memory, internal or external to the processor –bridge between the processor and RAM –including pipeline-burst simultaneous read/write Video memory –VRAM (“vee-ram”) –some graphic cards use other types of RAM

Ch 2© The McGraw-Hill Companies, Inc., CCI Ports External socket –front or back of system unit Parallel –printers, some Zip drives, some scanners Serial port (RS-232) –modems, scanners, mice Video adapter –digital and analog, single or dual monitor

Ch 2© The McGraw-Hill Companies, Inc., CCI More Ports SCSI: small computer system interface –fast –connected in daisy-chain fashion –originally used in Macs –can be internal or external –hard drives, tape backups, scanners, CD

Ch 2© The McGraw-Hill Companies, Inc., CCI Less Common Ports Game ports –joystick Infrared –often used for keyboards, mice, and printers

Ch 2© The McGraw-Hill Companies, Inc., CCI Expansion Slots Bus slots –for expansion cards and adapter cards –memory –video –graphics –controller –internal modem

Ch 2© The McGraw-Hill Companies, Inc., CCI Bus Designs ISA (“eye-suh”): Industry Standard Architecture –does not share common resources –16-bit PCI: peripheral component interconnect –some cards do share resources, such as IRQs –64-bit

Ch 2© The McGraw-Hill Companies, Inc., CCI More Buses EISA (“ee-suh”) enhanced industry standard architect –32-bit PCMCIA: Personal Computer Memory Card International Association –for PC cards on portable computers modems, hard drives, memory, Ethernet cards

Ch 2© The McGraw-Hill Companies, Inc., CCI Newer Bus USB –Universal Serial Bus –printer, scanner, digital camera, joystick, monitor –easy connection

Ch 2© The McGraw-Hill Companies, Inc., CCI Newest Bus AGP: Advanced Graphics Port –dedicated for video use –speed and access to memory and CPU continue to increase –more than double PCI rates –standards include 2X AGP, 4X AGP

Ch 2© The McGraw-Hill Companies, Inc., CCI Standards and Options New boards often have ISA and PCI slots so close together that both cannot be available for expansion at the same time The PC-2000 computer standard calls for no ISA slots

Ch 2© The McGraw-Hill Companies, Inc., CCI Future Processing Technologies Gallium arsenide – better conductor, fewer circuits than silicon Superconductors –electricity flows without resistance –100 x faster –refrigerated system units already on market

Ch 2© The McGraw-Hill Companies, Inc., CCI More of the Future Opto-electronic processing –use of light –in common with fiber optics Nanotechnology –nanometer = 1 billionth of a meter –molecules used to transform data or perform tasks

Ch 2© The McGraw-Hill Companies, Inc., CCI Future Biotechnology –use of bacteria for on/off signals