naba@eneevax.UUCP (Nabajyoti Barkakati) (10/07/85)
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I am using an IBM PC-AT with enhanced color display + enhanced graphics
adapter (EGA). I would like to use the display in its highest resolution
graphics mode (640x350) through the ROM-BIOS video services. By using
video mode 14, I could get 640X200 resolution, but mode 15 (which
supposedly means the EGA in extra high resolution) only messed up the
screen.
I would appreciate hearing from anyone who has used the EGA in the
640x350 resolution.
Thanks in advance.
Naba Barkakati
ARPA: enee!naba@maryland.ARPA
UUCP: [seismo,allegra]!umcp-cs!eneevax!naba mjm@cantor.UUCP (Michael Markowitz) (10/10/85)
Naba Barkakati has posted the following: > ======================================================================== > > I am using an IBM PC-AT with enhanced color display + enhanced graphics > adapter (EGA). I would like to use the display in its highest resolution > graphics mode (640x350) through the ROM-BIOS video services. By using > video mode 14, I could get 640X200 resolution, but mode 15 (which > supposedly means the EGA in extra high resolution) only messed up the > screen. > > I would appreciate hearing from anyone who has used the EGA in the > 640x350 resolution. > > Thanks in advance. > > Naba Barkakati > > ARPA: enee!naba@maryland.ARPA > UUCP: [seismo,allegra]!umcp-cs!eneevax!naba You might want to check out the April '85 issue of PC Tech Journal. It contains an article with a lot of technical info on the EGA. Anyway, I believe that your problem is that mode 15 (0fh) is intended to be used only for 50Hz monochrome displays--it won't work on the enhanced display. Try mode 16 (10h) for 640x350 graphics on that display. I recently rewrote one of the Mandelbrot set generating programs to work in this mode and the results are spectacular. With 128K on the EGA I get 16 colors. Unfortunately I haven't yet figured out how to dump the graphics memory (~112K) to disk so that the images can be stored, but if you like I would be willing to mail you a copy of what I've done to date. Hope this helps. Michael Markowitz Department of Math. Sciences Loyola University of Chicago UUCP: ihnp4!gargoyle!cantor!abel!mjm