mvolo@ecsvax.UUCP (Michael R. Volow) (06/23/89)
Will the original 6 MHz IBM AT support VGA cards without bios changes? We were trying to get a Video 7 VGA-16 card to work with such a com- uter, and could not get the comuputer to recognize it as a color card, no matter how we configured any settings (including the mono-color display switch in the AT, dip settings on the Video 7, or variations in the Setup configuration of the AT). It worked once when we moved it to an 8-bit slot but then mysteriously went back to mono. It will display, but in monochrome only. Any help would be appreciated. If you have responded to a similar posting by me yesterday already, no need to respond to this one. But we urgently need some advice on this problem. Thanks in advance. M Volow, VA Medical Center, Durham, NC 27705 mvolo@ecsvax.UUCP 919 286 0411
mike@relgyro.stanford.edu (Mike Macgirvin) (06/24/89)
In article <7244@ecsvax.UUCP> mvolo@ecsvax.UUCP (Michael R. Volow) writes: > >Will the original 6 MHz IBM AT support VGA cards without bios changes? >We were trying to get a Video 7 VGA-16 card to work with such a com- >uter, and could not get the comuputer to recognize it as a color card, >no matter how we configured any settings (including the mono-color >display switch in the AT, dip settings on the Video 7, or variations >in the Setup configuration of the AT). It worked once when we moved it >to an 8-bit slot but then mysteriously went back to mono. It will >display, but in monochrome only. Any help would be appreciated. If you The 'mysteriously went back to mono' caught my eye. I have at home a Paradise VGA-Plus and a Sony 1302. These two interact very strangely. This might have something to do with what you're seeing... If I turn on the computer power BEFORE the monitor power, the VGA card is not able to poll the monitor for its type, and it boots up B/W. If I turn on the monitor power BEFORE the computer power, I get no display at all (still can't figure out why) UNTIL I turn the monitor back OFF and then ON again (After the computer BIOS has initialized the display), then everything works in color. This is a generic XT clone. I would recommend setting the computer to color, and experiment with the timing of turning these things on. If somebody could explain why mine won't display until I reset the monitor power, I'd love to know.... it's a real hassle to not be able to just turn on ONE switch and go... +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + These views are my own, and may not be correct. + + Mike Macgirvin + + - Systems Administrator Stanford Relativity Gyroscope Experiment + + - Internet: mike@relgyro.stanford.edu (36.64.0.50) + + - Bitnet: mike%relgyro.stanford.edu@stanford + + - Uucp: uunet!relgyro.stanford.edu!mike + + "There must be some kind of way out of here." - Dylan (w/help from Jimi) + +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mvolo@ecsvax.UUCP (Michael R. Volow) (06/24/89)
Thanks to all who responded to my posting about our Video Seven VGA-16 not working with our 6Mz IBM AT. More careful seating of the cable in the socket on the board cured the problem. You were all correct that monitor must be on at boot time and the cable connections O.K. for the computer to recognize it as a color VGA. No further replies are necessary, and thanks again to all who helped. M Volow, VA Medical Center, Durham, NC 27705 mvolo@ecsvax.UUCP 919 286 0411
chasm@killer.DALLAS.TX.US (Charles Marslett) (06/26/89)
In article <239@helens.Stanford.EDU>, mike@relgyro.stanford.edu (Mike Macgirvin) writes: > In article <7244@ecsvax.UUCP> mvolo@ecsvax.UUCP (Michael R. Volow) writes: > > > > . . . It worked once when we moved it > >to an 8-bit slot but then mysteriously went back to mono. It will > >display, but in monochrome only. Any help would be appreciated. If you > The 'mysteriously went back to mono' caught my eye. I have at > home a Paradise VGA-Plus and a Sony 1302. These two interact very strangely. > This might have something to do with what you're seeing... If I turn on > the computer power BEFORE the monitor power, the VGA card is not able to > poll the monitor for its type, and it boots up B/W. If I turn on the monitor > power BEFORE the computer power, I get no display at all (still can't figure > out why) UNTIL I turn the monitor back OFF and then ON again (After the > computer BIOS has initialized the display), then everything works in color. > This is a generic XT clone. I would recommend setting the computer to > color, and experiment with the timing of turning these things on. If > somebody could explain why mine won't display until I reset the monitor > power, I'd love to know.... it's a real hassle to not be able to just turn > on ONE switch and go... Two problems seem to be appearing here: the monitor latches up in a no-display mode in one case, and the adapter fails to recognize the monitor in the other. Try this: Boot up normally (with the monitor turned on at the same time or after the computer is). Then when the VGA comes up in monochrome run a short program to turn off bits 1 and 2 of memory location 0040:0089. "MODE CO80" will now get you into a normal color mode (with most VGA cards). There is a BIOS call that turns off or on one of the two bits, but the other is intended to tell the software that a real monochrome VGA monitor is out there, so do everything in gray-scale. The program just overrules the original test the VGA BIOS did on the monitor /* No warranty on this code: */ #include <stdio.h> main() { unsigned char far *ptr = 0x00400089L; unsigned int k, m; k = *ptr; m = k & 0xF9; *ptr = k; printf("Original VGA flag byte = %02x, replaced with %02x\n", k, m); } The problem with the monitor remaining off if it is turned on before the computer may be related to a safety feature in the monitor (many do not like being on and not seeing a horizontal sync signal on the input). If this is the case, the monotor will be subject to unhealthy stress if it is turned on first (if the time is not long, it is unlikely to damage it, but it's better to be gentle to expensive electronic toys). > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > + These views are my own, and may not be correct. + > + Mike Macgirvin + > + - Systems Administrator Stanford Relativity Gyroscope Experiment + > + - Internet: mike@relgyro.stanford.edu (36.64.0.50) + > + - Bitnet: mike%relgyro.stanford.edu@stanford + > + - Uucp: uunet!relgyro.stanford.edu!mike + > + "There must be some kind of way out of here." - Dylan (w/help from Jimi) + > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ On the other hand, these views are my own, and may not be correct, but I'll never admit it!!!! =========================================================================== Charles Marslett STB Systems, Inc. <== Apply all standard disclaimers Wordmark Systems <== No disclaimers required -- that's just me chasm@killer.dallas.tx.us