Worksheet 2.3.2: PC Power Supply

  1. alternating, direct
  2. These enclose all the parts of the PC to protect them, direct the airflow, and contain RFI/EMI emissions.
  3. 5.25
    1. Type - must suit chosen motherboard
    2. Size - must have enough space for installed components plus access to them
    3. Power Supply - must be able to accomodate a suitable one
    4. Environment - must have air filters etc for dusty environment
    5. Status Display - to see basic diagnostic information
    6. Vents - need sufficient to dissipate heat generated by system
    7. Rigidity - must be strong enough not to flex in use
  4. 220/240, 110/120
  5. Typically 250W - 300W
  6. AT (legacy), ATX
  7. Circulates air inside the case to keep PSU and all the other electronics and devices cool

Worksheet 2.3.8: BIOS/ROM

  1. oprerating system, hardware
  2. ROM BIOS
  3. Basic Input/Output System
  4. Read Only Memory
  5. They can be erased and reprogrammed
  6. RAM can be both read and written under normal operation whereas ROM can only be read; but RAM loses its contents when powered off whereas ROM does not

Worksheet 2.3.9: Expansion Slots

  1. Receptacles on the computer's motherboard that accept printed circuit cards
  2. external, IO bus
  3. hardware devices
    1. ISA/EISA
    2. MCA
    3. VESA local
    4. PCI
    5. AGP
  4. Add-in cards contain information that the processor uses to automatically configure the card
    1. Video
    2. Sound
    3. Modem
    1. Address
    2. Data
    3. Control
  5. 8, 16 (bit bus widths)
  6. Data
  7. Peripheral Component Interconnect

Worksheet 2.4.2: RAM and RAM Sockets

  1. RAM
  2. Random Access Memory (ReAd/write Memory)
  3. The contents of RAM are lost when the computer power is turned off
  4. SRAM, DRAM
  5. DRAM
  6. An error checking capability
  7. Refresh
  8. IN a SIMM, the pads on the opposite sides of the board are connected to each other; in a DIMM, they are not
  9. Cache memory stores frequently used information and transfers it to the processor much faster than main memory

Worksheet 2.5.2: Video Cards

  1. digital, video (analog)
  2. graphics card, video adapter
  3. CPU (via the bus), monitor
  4. BIOS
  5. Cathode-Ray Tube
    1. red
    2. green
    3. blue
  6. dot pitch (or resolution)
  7. 15
  8. picture element
  9. Video Graphics Array

Worksheet 2.7.1: Floppy Drive

  1. It reads and writes information on a floppy disk which is a removable storage media suitable for text based data
    1. two heads located on either side of the disk move in unison to read and write data on the disk
    2. this controls all the functions of the drive
    3. attached to a worm-gear shaft to move the read/write heads to different tracks on the disk
    4. for mounting all the devices in the drive and to protect them
    5. clamps the center of the disk and spins it at 300/360 rev per min. It is attached to a small spindle motor
    6. opens the protective metal slide that covers the exposed part of the disk when the floppy disk is inserted in the drive
    1. plastic protective case
    2. thin magnetic flexible disk
    3. sliding door
    4. sliding door spring
  2. ribbon
  3. 2
  4. Mini-Plug

Worksheet 2.7.2: Hard Drive Identification

  1. Long term storage of both programs and data.
    1. for screwing cover to base casting
    2. round column connected to a motor to spin the attached platters
    3. convert bits to magnetic pulses for storage on the platters, reverse to read
    4. the disks that store the data, usually made of specially coated aluminium
    5. moves the actuator arm across the disk to seek different "tracks" of the data
    6. holds the read/write heads over the platters just enough so that they do not touch the surface of the disks
    7. single cast piece of metal to which all parts of the drive are mounted
    8. the media on which data is stored
  2. 4500 - 10 000
  3. local magnetic direction
  4. RLL (Run Length Limited) is an encoding method used on magnetic disks

Worksheet 2.7.3: CD-ROM Identification

  1. useful for installing programs, running applications that install some of the files to the hard drive, or to provide data to running programs
    1. grasps and spins the CD
    2. moves the tray in and out
    3. focuses the laser on the disk
    4. drives the spindle
    5. moves the laser pickup assembly to different tracks on the disk
    6. the laser is stored here
    1. 2X, 300kB/sec
    2. 4X, 600kB/sec
    3. 8X, 1.2MB/sec
  2. Molex (4-pin)
  3. to the sound card for direct audio playback
  4. up to 682MB
  5. SCSI