[comp.sys.ibm.pc] TI PC Graphics

leckie@enelc.uucp (02/02/89)

The TI Professional Computer has a reasonably good graphics screen
(700 x 300 x 3planes), however, it is incompatible with the "standard"
graphics cards (IBM-EGA,-CGA,-VGA, Hercules etc.). As I understand it,
programs that use graphics should communicate with the hardware through
BIOS, via interrupts. This being the case, would it be possible to
write an interrupt handler that would intercept commands to the
"standard" cards and send the information (suitably modified) to the
TI graphics adapter. Is anyone aware of the existence of such an
"emulate" utility.

Regards,
Brian Leckie
EE Grad. Student
Univ. of Calgary.

silver@eniac.seas.upenn.edu (Andy Silverman) (02/04/89)

In article <630@cs-spool.calgary.UUCP> leckie@enelc.uucp () writes:
>The TI Professional Computer has a reasonably good graphics screen
>(700 x 300 x 3planes), however, it is incompatible with the "standard"
>graphics cards (IBM-EGA,-CGA,-VGA, Hercules etc.). As I understand it,
>programs that use graphics should communicate with the hardware through
>BIOS, via interrupts. This being the case, would it be possible to
>write an interrupt handler that would intercept commands to the
>"standard" cards and send the information (suitably modified) to the
>TI graphics adapter. Is anyone aware of the existence of such an
>"emulate" utility.

Well, it would be nice if all those graphics programs wrote to the screen
using the BIOS, except the sad truth is that BIOS graphics routines are
invariably SLLLOOOOWWWWWW, and to achieve blazing-speed-graphics all the
major programs determine what video adapter is in use and then write directly
to screen memory and/or manipulate the screen controller ports.  Since the
TI Professional has such non-standard hardware and non-standard memory
mapping, writing such an interrupt handler would be essentially impossible
since interrupts are rarely used in graphics programming.  Incidentally, TI
includes a program EMULATE.COM with the TIPC which allows emulation of the
text modes and solves a few other minor incompatibilities, but unfortunately
graphics is not among them.  Sorry to be the bearer of bad tidings...




Andy Silverman
Internet: silver@eniac.seas.upenn.edu
CompuServe: 72261,531

news@SJ.ATE.SLB.COM (USENET News System) (02/11/89)

Just in case any one cares the graphics resolution on the TI Pro is
not 700 x 300 but 720 x 360.
From: grimesg@makalu (George Grimes)
Path: makalu!grimesg

George Grimes
TI Pro owner

herman@mips.csc.ti.com (Herman Schuurman,Adv. Autom.E,0638,6444198) (02/14/89)

From article <669@snjsn1.SJ.ATE.SLB.COM>, by news@SJ.ATE.SLB.COM (USENET News System):
> Just in case any one cares the graphics resolution on the TI Pro is
> not 700 x 300 but 720 x 360.
> 
> George Grimes
> TI Pro owner
Actually, it's 720 horizontal x 300 vertical, stored in three separate
bit planes located at C0000, C8000 and D0000.  Each line of 720 pixels
is stored in 46 16-bit words (there is one unused word at the end of each
line).  This means that 720x360 would require 92x360 = 33120 bytes per
plane, which is more than is available (32k per plane).

Herman Schuurman