Hard Drives

Floppy Drives

System Board Components Used for Communication Among Devices
Bus
System clock
Expansion slots
PCI:  Used for high-speed input/output devices
AGP:  Used for a video card
ISA:  Used by older and/or slower devices

Bus Lines

System Clock

Expansion Slots

Expansion Slots

Interface (Expansion) Cards
Circuit boards inserted into a slot on the system board to enhance capability of the computer
Common types
Video card
Network card
Internal modem
I/O controller card
Network card

Video Card

The Electrical System
Power supply
Supplies power to the system board and other installed devices
Provides 3.3, 5, and 12 volts DC

The Electrical System

The Electrical System

Instructions and Data Stored on the System Board
ROM chips
Contain permanent programming code
Sometimes called BIOS chips
CMOS configuration chips
Hold configuration or setup information
Jumpers or DIP switches
Hold configuration information

ROM BIOS Chip on a Video Expansion Card

ROM BIOS Chip on the System Board