ATX is a development of the
Baby AT specification with the
motherboard rotated 90 degrees in the chassis. The
CPU and
SIMM sockets have been relocated away from the
expansioncard slots meaning that all the slots support full-length
cards. More
I/O functions are integrated on the
motherboard. As the longer edge of the board is now at the
back of the chassis, there is more space for connectors; also,
the I/O opening on the back panel of the chassis has been
defined as double the previous height, allowing vendors to add
extra on-board I/O functions over and above the standard.
As well as the motherboard size, layout, and placement, the
ATX specification also includes requirements for power supply
and fan specification and location.
The full size ATX board measures 305mm wide by 244mm deep.
There is also a Mini-ATX form factor, 284mm by 208mm.
(2001-07-16)