Xycom 9465 PC/AT, Manual, Page: 37 / 87

9465/9465KPM System Manual
3-22
Note
It is not necessary to read this section if you are a Windows 95, Win-
dows NT, or OS/2 user, do not plan to run DOS applications, and have
not modified the default expansion mode in the BIOS setup menus.
Unlike a CRT, a flat panel display has a fixed horizontal and vertical resolution. There
are many DOS video modes whose resolution is less than that of a flat panel display. To
more efficiently make use of the flat panel display’s active area, it is necessary to employ
an expansion technique that stretches the lower resolution information to fill the higher
resolution of the display. For example, DOS defaults to VGA video mode 3+. This is an
80 column, 25 row text only screen whose effective resolution is 640 dots x 400 scan
lines. Because of this, the 1024 x 768 display of the 9465 will be partially filled by the
640 x 400 resolution of this particular mode. By enabling the expansion function, these
lower resolutions will better utilize the display by stretching the information in an at-
tempt to fill the display. Operating systems such as Microsoft Windows 3.X, Windows
95, and Windows NT use display drivers to handle the different flat panel displays. Ex-
pansion is not necessary since there is a specific driver for each resolution.
Expansion does not add any resolution to the existing information; it simply stretches the
information to better fit the display. Text and graphic screens can look somewhat grainy
after expansion.
You can turn expansion off in the BIOS setup menus, or by executing an included utility
program. See the table below for the three utility programs included to allow expansion
to be turned on, turned off, and set back to the BIOS default state and what effect they
have on the display.
9465 Video Expansion Options
Utility Mode Panel Type/Size
15" STN 13.8" TFT
EXP_ON.EXE Text Vert/Hor Vert/Hor
Expansion On Graphics Vert/Hor Vert/Hor
EXP_DEF.EXE Text Off Vert/Hor
Expansion Default Graphics Off Off
EXP_OFF.EXE Text Off Vert/Hor
a
Expansion Off Graphics Off Off
Definitions:
Vert:
Vertical only expansion is invoked
Vert/Hor: Vertical and Horizontal expansion is invoked
Expansion Default: The video BIOS default on power up
a
Text expansion cannot be turned off.
On a 1024 x 768 display, the stretching algorithm does not completely fill the display
horizontally or vertically. You can achieve a greater vertical text expansion by changing
to VGA mode 3* (see Note below). This is an 80 column, 25 row text mode with an ef-
fective resolution of 640 x 350. The 350 lines stretch better to fill the 768 line display.
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