How many LUTs for a 6845 emu/simu/clone ???
FPGA found on PCI parallel card, possibilities???

furan wrote on 2026-04-21, 23:28:

I don't know why we're talking about supporting a theoretical additional cga card that is pci though - at this point just make a nice vga core that has extra cga/hercules bells and whistles.

wierd_w wrote on 2026-04-22, 00:16:

Many people want to drive a vintage CRT, which you cannot do with VGA signals.

Again: the idea is to re-create Mach32 functionality.
Additionally, install both VGA and TTL connectors, just like on many early VGA clones.

Well you can use Tomi Engdahls VGA2TV to get VGA chipsets to put out 15khz. Some of the early PCI chipsets should work with it, CL GD5434 is a cert, but not sure about others, Trident TGUI maybe. So out of those need to find the one with best CGA support. Then it's a matter of TTL conversion of the VGA output. This gets you a picture on a CGA tube, but not entirely sure if it's "real CGA" in number of lines... since it's emulated CGA that would be line doubled for VGA getting scan converted to CGA rates.

Thank you all for your replies! 😀 What I really want is maybe not a PCI CGA card, but a VGA card with almost perfect CGA emulation.
The PCI Ati Mach32 was mentioned, I'll try to get one. Would it work if I put a Trio64 and a Mach32 into the same PC? I would plug the VGA cable to either one of them, depending on which game I want to play, then I would turn the computer on. Or can I unplug the cable while the PC is running and plug it in the other card? I'm wondering if that would do any harm to the PC or to the screen.

kaposzta wrote on 2026-04-24, 13:48:

Thank you all for your replies! 😀 What I really want is maybe not a PCI CGA card, but a VGA card with almost perfect CGA emulation.
The PCI Ati Mach32 was mentioned, I'll try to get one. Would it work if I put a Trio64 and a Mach32 into the same PC? I would plug the VGA cable to either one of them, depending on which game I want to play, then I would turn the computer on. Or can I unplug the cable while the PC is running and plug it in the other card? I'm wondering if that would do any harm to the PC or to the screen.

No, I highly doubt it will work.
I'm certain the VGA bioss will cause problems, that and the fact that both vga cards will likely expect to be the only vga card in the system, thus causing no boot or strange boot display issues.
Even if one card is pci and the other is AGP.

From what I recall, it's possible to use two PCI VGA cards at the same time.

The first one is assigned all requested resources: VGA compatible + PCI specific
The second one: PCI specific only

With normal DOS software, you can only use the first one.
The second one is available for systems with multiple-display support, eg. Windows 98.

I don't know whether it's possible to choose which of the cards should be the first one...

Edit: with PCI VGA + AGP VGA, it should work as above, additionally there's the "Init display first: PCI/AGP" BIOS option.

2 PCI cards does work, but maybe not until PCI 2.0, triton chipsets at least. Win98SE makes it easy to do dual monitor, but prior OS will probably be a mess. However, POST and dos console should initialise on whichever have monitor plugged in. Some picky picky motherboards might give you the beeps for not having a monitor plugged into one of them, whichever it thinks is more important. Beware if you use a VGA switcher that it's not a fancy one with resistors to fake monitor presence, otherwise the selection by monitor connection may not work that way. I'd recommend something like that though to save VGA socket wear.