X11 expertise on ancient HW sought... (4-plane visual (overlay) via X-server on MS-WIndows)

[Maciej W. Rozycki]

On Sat, 6 Jun 2015, IMAP List Administration wrote:

> Depending on the cost, hacking the X-Server might be an option.
> I have presented MS-Windows as a given here, but in fact I could also use Linux.
> Do any possibilities involving Linux occur to you?

 What kind of use do you require here for your app -- is that a one-off 
installation or a more widespread deployment?

 For a single use your simplest solution might be using similar hardware.  
ZLX-E2 is the PMAGD-B or HX+ TURBOchannel option (24-bit DirectColor, no 
Z-buffer, using a Bt463 RAMDAC), also known as SFB+ (Smart Frame Buffer+) 
after the graphics ASIC.  A 5V PCI variant was manufactured under the name 
of ZLXp-E2, more commonly known as TGA (I don't know offhand what the 
acronym expands to).  Both are supported under Linux, using the `tgafb' 
kernel driver and a corresponding X11 DDX module.

 So you might try this instead, chasing a 24-plane PCI TGA board should be 
doable.  The board has no VGA compatibility AFAIK so there should be no 
odd issues with legacy address decoders or initialisation on non-Alpha 
systems -- the board should simply sit there quietly until initialised by 
the kernel driver and then taken over by the X server.  The DDX module for 
the X server might not be built by default for TGA on non-Alpha systems 
though, so you might have to do some tweaking.

 Just a thought, maybe it'll help.

  Maciej