I haven't found how that's done, yet. I mean the card can lock or bypass the palette registers in the lower modes somehow, on a HW level because I've tried that, but I don't think it's the CRTC job. So my guess there is some other register with a bit that disables this, independent of resolution? …

I'm not sure I can help you much (never having seen a 3270AT in action) but I hope you are able to get it working. How does the keyboard connect? Is it like the 3270PC where it goes through a Y-cable, or does it just plug into the motherboard keyboard port? Looking at the AT BIOS source , POST code …

You're correct that it's checking for PPC hardware - specifically, the video hardware. It writes to the CGA mode control register (03D8h) and checks that the video NMI system modifies the value written. The conditional jump to be patched out is at offset 5796 in RUNALC.EXE - replace 75 17 with 90 …

I just sent an email to John Elliott - I think if anyone is likely to know, it'd be him. John sent me this link to a newsgroup post by Roland Perry which confirms that, yes, indeed the 40041 in the PC1640 is vestigial - apparently it was just cheaper to build them that way! In this thread you …

emendelson wrote: I'd be very interested to see if the WordPerfect Genius-monitor drivers work with this. Is there a Windows download available for PCEM with Genius support? There is now -- v13.1.

I'd be very interested to see if the WordPerfect Genius-monitor drivers work with this. Is there a Windows download available for PCEM with Genius support? The current web page doesn't mention it. And of course if you're interested in trying this yourself, I can supply a copy of WPDOS 5.1 with the …

I've documented what I know of the Genius hardware here. While there are some unanswered questions, I was able to implement enough of it in PCEM that the GEM and Windows 1.x drivers worked -- so it should be possible to add the same level of support to DOSBox if required.

Here's something that may help with the Tecmar card: ftp://ftp.ucl.ac.uk/pub/users/ucklddc/dcprogs/hgraph/ has a whole set of configuration files for different graphic modes -- and tecmar.cfg gives the parameters for the 640x400 interlaced mode. By comparing it with CGA.CFG, it ought to be possible …

The zip contains both source code and the compiled .APP . To run it you just need SETTINGS.APP and GEMSET.RSC, not any of the other files.

http://www.seasip.info/Gem/Software/win95.cfg is my quick attempt at creating one. The colour editor is SETTINGS.APP -- I recommend downloading the latest one from http://www.seasip.info/Gem/Software/settings.zip , as previous versions had some usability problems with the colour chooser.

Here's how it's done: http://www.seasip.info/VintagePC/hercplus.html. And if you want a challenge, the InColor card too: http://www.seasip.info/VintagePC/incolor.html