Motherboard aka (system board, planar board, main board, logic board)

Motherboard manufacturers Tyan, Intel, Gigabyte, Shuttle and Asus

Motherboard is the main circuit board of a microcomputer.

AT / ATX DIFFERENCES

The following is some of the ways in determining if your motherboard is an AT motherboard or an ATX motherboard.

The Keyboard:
AT Motherboard = DIN/5 connector

ATX Motherboard = PS/2 connector

Motherboard power connector
AT Motherboard = Single Row two connectors 5v & 12v
ATX Motherboard = Double row single connector 5v, 12v, and 3.3v
In this section, you learned that the motherboard holds all the components of the computer that serves as their main attachment point.

What components are found on a typical motherboard

CPU type: CPU socket or CPU slot
Memory slots: SIMM slots, DIMM slots or RIMM slots
Cache memory: Internal or External Cache found on the CPU and as support chips
Chipsets: Northbridge, Southbridge, Cache, Heatsink, MCC, sound and video chipsets
System BIOS: ROM usually a DIPP chip and complemented by the CMOS battery
Expansion slots: AGP, ISA, PCI, AMR and CNR
Motherboard connectors: FDC, IDE Controllers, Fan Controllers, CD/DVD and sound controllers
Motherboard settings: Jumpers and Switches
Power connectors: AT socket vs. ATX socket

Types of motherboards

(old school)
AT (Full vs. Baby)
XT (rip)
LPX (rip)

(newer)
ATX vs. BTX motherboard

NLX Motherboard

Full-AT (12" wide x 13.8" deep) Matches the original IBM AT motherboard design, which only fits into full size AT or tower cases only, not being produced much any more if any. This form factor is no longer produced because it cannot be placed into the popular Baby-AT chassis.

Baby- AT (8.57" wide x 13.04" deep) Almost the same as the original IBM XT motherboard with modifications in the screw hole position to fit into AT style case, with connections built onto the motherboard to fit the holes in the case

A. Primary and Secondary IIDE Controllers
B. ROM/BIOS
C. ISA slots
D. CMOS Battery
E. PCI slots
F. DIN/5 Keyboard Connector
G. AT Socket
H. ATX Socket
I. DIMM Slots
J. SIMM Slots
K. Chipset
L. L2 Cache
M.CPU Socket
N. Floppy Drive Controller
O.LPT Connector
P.COM Connector