1.2.4 VGA
The VGA is a graphics controller on the system board. The VGA supports
color and monochrome analog direct-drive displays in a variety of modes,
including alphanumeric text mode, and all-points-addressable (APA)
graphics mode.
The VGA supports a maximum of 720-by-400 picture elements (PELs) in the
text mode and 640-by-480 PELs in the graphics mode. The VGA can support
256 colors or 64 shades of gray at one time. Composite video is not
supported.
Model 80 systems can have either one or two 16-bit extended expansion
slots on the system board. These slots extend farther to the rear of the
system board than the others. The extended expansion slots accommodate
video adapters that are designed to interface with the system-board VGA.
Some of these adapters provide a display connector of their own. The
extended expansion slots also support all adapters designed to be
installed in the shorter slots.
Warning: Some non-IBM graphics adapters drive rather than receive VGA
signals. If more than one adapter that drives a VGA signal is installed
in a system, both adapters will be damaged.
IBM PS/2 Model 80 HMR
VGA
¦ Copyright IBM Corp. 1990
1.2.4 - 1
