Archived from groups: comp.sys.ibm.pc.hardware.video (
More info?)
George R. Gonzalez wrote:
> I'd like to run the wonderful watcom debugger on a separate CRT on
> a newer PC, under Windows XP.
>
> But the other "debugger screen" crt has to be the oooollldd MDA
> kind. Watcom doesnt support a separate VGA debugger screen yet.
I don't know the Watcom debugger. I suppose it needs a real DOS session?
If it can open a normal Windows you could use a generic Windows XP
multi-monitor setup.
> So the question is:
>
> Is there a Monochrome Display Adapter for PCI bus???
I very much doubt that. If this is really important for you you could
get a board with an ISA slot (but you probably couldn't use that for
your main system).
> Or has anyone written a tricky driver that emulates MDA?
AFAIK nearly all VGA cards have MDA emulation. In DOS or maybe Win9x you
can try 'mode mono' to try this. But I don't think it is possible to put
a secondary VGA card into monochrome mode because the register needed to
switch to monochrome mode (Port 3d6h index 14h) is only active on the
primary video card. All VGA compatible registers have to be hidden on a
card to enable it to run as secondary (some cards like S3 Virge can't do
this so you can only run them as primary).
If you can convice Windows to run *only* on the secondary video card
(ie. the video card which is not active at boot time) and not to install
drivers for the primary video card then you might have a chance to
switch the primary card to monochrome mode (Bit of software hacking is
required since Windows prevents you from accessing the hardware
directly. Look for GiveIO or similar tools.)
Another idea: In some BIOS setups (mainly in older Award BIOSes) there
is an option in the Standard CMOS setup for the video mode which you can
set to mono. You could try if this will switch a VGA card to mono mode.
Please tell if you managed to do this, that would be a really
interesting hack. I didn't find anything like that with Google but maybe
I just didn't find the right keywords.
André
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