24. Computer Basics
24
• ROM (read-only memory) is
nonvolatile memory
–Holds program instructions after
power off
–Instruction set for startup
–BIOS (basic input/output system)
25. Computer Basics
25
• CMOS (complementary metal
oxide semiconductor)
–permanent as long as battery voltage
is applied
–Holds PC setup
–User intervention
26. Computer Basics
26
Still other ICs are PGA (pin-grid array) a
square chip package used for the main
processing circuitry.
31. Computer Basics
31
•ISA (industry standard architecture).
– ISA slots are an older technology, used
today for some modems and other relatively
slow devices. Many new computers have few
or no ISA slots
33. Computer Basics
33
•PCI (peripheral component interconnect).
– PCI slots offer fast transfer speeds and a 64-bit
data bus. These slots typically house a graphics
card, sound card, video capture card, modem, or
network interface card (NIC).
35. Computer Basics
35
•AGP (accelerated graphics port).
– Primarily used for graphics cards, and faster
than a PCI slot, an AGP slot provides a high-
speed data pathway that is particularly handy
for 3-D graphics.
46. Computer Basics
46
CONNECTORS
Connects to parallel port,
which sends data
simultaneously over
eight data lines at
speeds of 12,000 Kbps
(kilobits per seconds)
LPT
Printer,
external
CD-ROM
drive,
external
Zip,
external
hard drive.
25 pins
49. Computer Basics
49
CONNECTORS
Scuzzy
Connects to SCSI port, which sends
data simultaneously over 8 or 16 data
lines at speeds between 5 Mbps and
80 Mbps (Mega bits per second).
Can support
up to 16
devices in a
“Daisy
Chain”. Hard
drives,
scanner, CD-
ROM, tape
backup.
50 pins
52. Computer Basics
52
• Magnetic media
–Floppy disks
• 3.5”
• 5.25”
–Hard disk
–Zip Disk
–Tape
– used for backup
Memory storage at present fall into three basic
categories.
53. Computer Basics
53
• Optical storage media
–CD-ROM
• compact disk - read only memory
–DVD
• digital video disc or digital versatile disc
Memory storage at present fall into three basic
categories.