4 1 Computer Hardware Ch.5-A,B,C,D; Ch.4-B FALL 2000 Rob Wolfe

4 DIT Wolfe 2Goal Identify the components that are on the main circuit board of a microcomputer Identify the components that are on the main circuit board of a microcomputer Explain how RAM, virtual memory, CMOS and ROM differ Explain how RAM, virtual memory, CMOS and ROM differ Explain how the CPU performs the instructions contained in a computer program Explain how the CPU performs the instructions contained in a computer program List the factors that affect CPU performance List the factors that affect CPU performance More… More…

4 DIT Wolfe 3 Goal (continued) Describe how the data bus and expansion bus work Describe how the data bus and expansion bus work List the components necessary to connect a perifheral device to a computer and describe each component’s role List the components necessary to connect a perifheral device to a computer and describe each component’s role Trace the boot process of your computer system Trace the boot process of your computer system

4 DIT Wolfe 4 Computer Hardware as a System Input Devices Processor Output Devices

4 DIT Wolfe 5 Computer Hardware as a System Input Devices Processor Output Devices Secondary Storage Devices Telecom Devices CPU RAM

4 DIT Wolfe 6 Integrated Circuits Integrated circuit (IC) — a thin slice of crystal packed with microscopic wires, transistors, capacitors, and resistors. Integrated circuit (IC) — a thin slice of crystal packed with microscopic wires, transistors, capacitors, and resistors. Chips (microchips) — a common name for integrated circuits. Chips (microchips) — a common name for integrated circuits.

4 DIT Wolfe 7 The Motherboard CPU chip CPU chip Memory chips Memory chips Circuits (paths) for transporting data Circuits (paths) for transporting data Chips for basic input and output Chips for basic input and output Expansion slots Expansion slots Main board or motherboard — an integrated circuit board that contains...

4 DIT Wolfe 8 Digital v. Analog Data Representation Analog devices Digital devices

4 DIT Wolfe 9 Digital Data Representation numeric character numeric Numeric data or character data ? Annual income Name Social Security number Street address Phone number Price of software Grade point average

4 DIT Wolfe 10 Types of Memory RAM (random access memory) RAM (random access memory) Virtual memory Virtual memory ROM (read-only memory) ROM (read-only memory) CMOS memory CMOS memory

4 DIT Wolfe 11 Random Access Memory Capacitor — holds an electronic signal, or bit Capacitor — holds an electronic signal, or bit A charged capacitor represents an “on” bit A charged capacitor represents an “on” bit Capacitors are arranged in banks of eight, holding one byte of data Capacitors are arranged in banks of eight, holding one byte of data Each bank of eight capacitors has a RAM address Each bank of eight capacitors has a RAM address

4 DIT Wolfe 12 Random Access Memory RAM is volatile RAM is volatile RAM is a reusable resource RAM is a reusable resource If the power goes off, all data stored in RAM is instantly and permanently lost If the power goes off, all data stored in RAM is instantly and permanently lost The contents of RAM must be reloaded each time the computer is turned on The contents of RAM must be reloaded each time the computer is turned on

4 DIT Wolfe 13 Virtual Memory Virtual Memory — computer’s ability to use hard disk space as an extension of RAM. Not as fast as RAM Not as fast as RAM Allows computers without enough real memory to run large programs Allows computers without enough real memory to run large programs Like RAM, it becomes inaccessible if the power goes off Like RAM, it becomes inaccessible if the power goes off

4 DIT Wolfe 14 Read Only Memory Read-only memory (ROM) — a set of chips containing instructions that help a computer prepare for processing tasks. Read-only memory (ROM) — a set of chips containing instructions that help a computer prepare for processing tasks. Basic Input Output System (ROM BIOS) — a set of instructions that tells the computer how to access disk drives. Basic Input Output System (ROM BIOS) — a set of instructions that tells the computer how to access disk drives.

4 DIT Wolfe 15CMOS CMOS (complementary metal oxide semi- conductor) memory — A chip that semi-permanently contains data about the computer configuration A chip that semi-permanently contains data about the computer configuration It is powered by battery to retain its contents It is powered by battery to retain its contents Can be altered if the system configuration changes Can be altered if the system configuration changes

4 DIT Wolfe 16 Central Processing Unit Holds data and instructions Processes data and instructions

4 DIT Wolfe 17 Central Processing Unit Three Components Three Components Control Unit Registers ALU

4 DIT Wolfe 18 Input and Output Computer input/output (I/O) refers to collecting data for the microprocessor to manipulate and transport results to display, print, and storage devices. Computer input/output (I/O) refers to collecting data for the microprocessor to manipulate and transport results to display, print, and storage devices. The data bus transports data and instructions between RAM and the CPU. The data bus transports data and instructions between RAM and the CPU. The expansion bus is the segment of the data bus that transports data between RAM and peripheral devices. The expansion bus is the segment of the data bus that transports data between RAM and peripheral devices.

4 DIT Wolfe 19 Input and Output

4 DIT Wolfe 20 Secondary Storage Storage device — mechanical apparatus that records and retrieves data. Storage device — mechanical apparatus that records and retrieves data. Storage medium — disk, tape, or other substance that contains data. Storage medium — disk, tape, or other substance that contains data. Magnetic or Optical? Magnetic or Optical?

4 DIT Wolfe 21 Magnetic or Optical? Magnetic Technology Fairly permanent Fairly permanent Easy to modify Easy to modify Data can be altered unintentionally Data can be altered unintentionally Average life is 3 years Average life is 3 years Optical Technology Permanent Permanent Cannot be modified Cannot be modified Data cannot be intentionally changed or erased Data cannot be intentionally changed or erased Durable device Durable device Average life is 500 years Average life is 500 years

4 DIT Wolfe 22 DASD v. SASD DASD (Direct Access Storage Device) DASD (Direct Access Storage Device) SASD (Sequential Access Storage Device) SASD (Sequential Access Storage Device)

4 DIT Wolfe 23 In Review Identify the components that are on the main circuit board of a microcomputer Identify the components that are on the main circuit board of a microcomputer Explain how RAM, virtual memory, CMOS and ROM differ Explain how RAM, virtual memory, CMOS and ROM differ Explain how the CPU performs the instructions contained in a computer program Explain how the CPU performs the instructions contained in a computer program List the factors that affect CPU performance List the factors that affect CPU performance More… More…

4 DIT Wolfe 24 In Review (continued) Describe how the data bus and expansion bus work Describe how the data bus and expansion bus work List the components necessary to connect a perifheral device to a computer and describe each component’s role List the components necessary to connect a perifheral device to a computer and describe each component’s role Trace the boot process of your computer system Trace the boot process of your computer system

4 DIT Wolfe 25Review