PDA

View Full Version : Help with an XT clone and CGA card: monochrome vs color monitors



Load"*",8,1
October 28th, 2013, 06:06 PM
I finally got my hands on an XT-class machine. But I can only get it to display to a monochrome monitor. When I plug in a color monitor (I have an IBM PC Color Monitor and a Tandy CM-5), I just see garbled horizontal lines zipping down the screen (in green on the IBM monitor and gray on the Tandy monitor).

The graphics card in the computer is a "CT-6040r", which as near as I can figure from the sparse results of a googling, is an 8-bit CGA and parallel port card... so I presume it ought to work. But I can't figure out how to *get* it to work. (I also can't figure out how to access the bios. Does anyone know anything about the "DTK/ERSO/BIOS"?)

Trixter
October 29th, 2013, 10:55 AM
If you run a program on it that only displays CGA graphics, and it does not run, then what you have is actually a monochrome/MDA card and not a CGA card. Try running an early game on it like Alley Cat or Robotron and see what it does.

vwestlife
October 29th, 2013, 11:34 AM
It may be a dual-mode CGA/MDA card. If you can get to a DOS prompt, type MODE CO80 and see if that produces a proper CGA color signal out of it.

modem7
October 29th, 2013, 02:58 PM
There was a CT-6040S (CT-6040S, not CT-6040R) offered on eBay.

Someone had placed a "Mono" sticker on that card. That was backed up by the fact that "MGP" was printed in bold on the card:
MGP = monochrome graphics adapter with printer port

Does the CT-6040R also have "MGP" printed on it?

modem7
October 29th, 2013, 02:59 PM
(I also can't figure out how to access the bios. Does anyone know anything about the "DTK/ERSO/BIOS"?)
That BIOS is not configurable (no SETUP like in an AT-class computer).

Load"*",8,1
October 29th, 2013, 03:26 PM
Ah. Yes, it does. There you go then: it's a Monocrhome Display and Parallel Port card.

So I guess I need to find a proper CGA card then. Thanks!

Load"*",8,1
October 29th, 2013, 03:29 PM
Ah. Yes, it does. There you go then: it's a Monocrhome Display and Parallel Port card.

So I guess I need to find a proper CGA card then. Thanks!