(^74) PC Hardware: A Beginner’s Guide
The IBM PC XT
The successor to the IBM PC was the IBM PC XT (Extended Technology). The mother-
board of the PC XT was about the same size, but it included three more expansion slots
(eightcomparedtofive)andreplacedthecassettetapewitha5.25-inchfloppydiskdrive.
Form Factor
Width
(in inches)
Length
(in inches) Design Type Case Type
IBM PC 8.5 13 Motherboard IBM PC
IBM PC XT 8.5 13 Motherboard IBM PC XT
AT 12 11-13 Motherboard AT Desktop
or Tower
Baby AT 8.5 10-13 Motherboard Baby AT
Desktop
or Tower
LPX 9 11-13 Backplane Low profile
Micro-AT 8.5 8.5 Motherboard Baby AT
Desktop
or Tower
ATX 12 9.6 Motherboard ATX Desktop
or Tower
Mini-ATX 11.2 8.2 Motherboard Smaller ATX
Desktop
Mini-LPX 8-9 10-11 Backplane Low profile
Micro-ATX 9.6 9.6 Motherboard Low profile
NLX 8-9 10-13.6 Backplane Low profile
Flex-ATX 9 7.5 Motherboard Flexible design
Table 4-1. Motherboard Form Factors