Connectors; Problems With The Hp D2800A 21-Inch Display; Video Memory - HP Vectra VE5 3 Series Technical Reference Manual

3 Interface Boards and Mass-Storage Drives
SiS 6205 Graphics Controller Chip

Connectors

The Video Electronics Standards Association (VESA) defines a standard
video connector, variously known as the VESA feature connector,
auxiliary connector, or pass-through connector. This graphics controller
supports an output-only VESA feature connector, which has been
integrated on the system board and is connected directly to the pixel data
bus and the synchronization signals. Its pin names are listed on page 34.

Problems With the HP D2800A 21-Inch Display

This trade-off, between making the rise and fall times of video signals too
short or too long, works well with the SiS 6205 video controller driving all
types of HP display except one: the HP D2800A 21-inch display. With this,
the signal rise and fall times prove to be too short, and the effect of signal
overshoot, small though it is, might become apparent to some users, and
may disturb sensitive eyes. It causes an over-brightness after sudden black-
to-white or white-to-black transitions. This can occur within text strings
that are made up of thin characters, or along single dot-wide lines.
It is a purely subjective effect. However, in general, the use of this display
with the HP Vectra VE 5/xxx series 3 is not recommended. If the user is
determined to use this combination, though, then decreasing the refresh
rate or the video resolution, or both, may diminish the effect.

Video Memory

A portion of the main memory is used as frame buffer (video memory). It is
non-trivial to determine exactly into which physical memory chips the POST
will place the video memory (that is, where it will be positioned in the
memory map).
The size of the video memory can be configured by software or by the Setup
program. Increasing the amount of video memory causes the amount of
main memory that is available for system use to be reduced.
SystemMemory = MainMemory - VideoMemory
The default setting is for 1 MB video memory. This can be increased to
2 MB. Alternatively, if the POST detects the presence of an external
graphics board, with its own video memory, the full amount of main memory
is allocated for use as system memory.
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