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Processing Hardware Chapter 2 Turning Data into Something You Can Use © The McGraw-Hill Companies, Inc., 2000 Overview • Data and program representation • Processor, main memory, registers • RAM capacity, word size, processor speed • Microcomputer Ch 2 © The McGraw-Hill Companies, Inc., 2000 2 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., 2000 3 CCI Data and Program Representation • Binary system • Two common schemes – EBCDIC – ASCII • New scheme – Unicode Ch 2 © The McGraw-Hill Companies, Inc., 2000 4 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., 2000 5 CCI Capacity • Bit – 0s and 1s • Byte – 8 bits • Kilobyte – about 1000 bytes Ch 2 © The McGraw-Hill Companies, Inc., 2000 6 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., 2000 7 CCI Processor • Information – manipulates data into useful information • Knowledge – results in reasoned analysis and applications Ch 2 © The McGraw-Hill Companies, Inc., 2000 8 CCI Processors, Main Memory, and Registers • Processor – control unit – arithmetic/logic unit (ALU) Ch 2 © The McGraw-Hill Companies, Inc., 2000 9 CCI Logical Operations • Logical operations in the ALU are simple comparisons such as =, <, >, <=, or >= Ch 2 © The McGraw-Hill Companies, Inc., 2000 10 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., 2000 11 CCI Specialized Systems • Coprocessors – math – graphics Ch 2 © The McGraw-Hill Companies, Inc., 2000 12 CCI Future • PC on a chip Ch 2 © The McGraw-Hill Companies, Inc., 2000 13 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., 2000 14 CCI MPP • Massively parallel processing (MPP) – spreads calculations over many computers or processors Ch 2 © The McGraw-Hill Companies, Inc., 2000 15 CCI Main Memory • Primary storage – RAM (random access memory) • • • • Ch 2 holds data instructions processed data for output is volatile © The McGraw-Hill Companies, Inc., 2000 16 CCI Main Memory Facts • Contents temporary • Capacity varies according to installed amount of memory chips Ch 2 © The McGraw-Hill Companies, Inc., 2000 17 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., 2000 18 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., 2000 19 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., 2000 20 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., 2000 21 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., 2000 22 CCI Focus on PC Purchasing – System unit • Hard drive • Floppy drive (except iMac) • Power supply • Motherboard • Microprocessor • Ram Ch 2 • ROM • Cache • VRAM • Ports • Expansion boards • Bus lines • PC slots • PC cards © The McGraw-Hill Companies, Inc., 2000 23 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., 2000 24 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., 2000 25 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., 2000 26 CCI Other Microprocessors • Motorola (Mac) – – – – – – – Ch 2 68000 68020 68040 PowerPC 601 PowerPC 604 PowerPC 620 PowerPC 750 © The McGraw-Hill Companies, Inc., 2000 27 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., 2000 28 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., 2000 29 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., 2000 30 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., 2000 31 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., 2000 32 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., 2000 33 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., 2000 34 CCI More Ports • SCSI: small computer system interface – – – – – Ch 2 fast connected in daisy-chain fashion originally used in Macs can be internal or external hard drives, tape backups, scanners, CD © The McGraw-Hill Companies, Inc., 2000 35 CCI Less Common Ports • Game ports – joystick • Infrared – often used for keyboards, mice, and printers Ch 2 © The McGraw-Hill Companies, Inc., 2000 36 CCI Expansion Slots • Bus slots – – – – – – Ch 2 for expansion cards and adapter cards memory video graphics controller internal modem © The McGraw-Hill Companies, Inc., 2000 37 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., 2000 38 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., 2000 39 CCI Newer Bus • USB – Universal Serial Bus – printer, scanner, digital camera, joystick, monitor – easy connection Ch 2 © The McGraw-Hill Companies, Inc., 2000 40 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., 2000 41 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., 2000 42 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., 2000 43 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., 2000 44 CCI Future • Biotechnology – use of bacteria for on/off signals Ch 2 © The McGraw-Hill Companies, Inc., 2000 45 CCI