Qbccd wrote on 2026-04-19, 21:08:

It's a variation of an ultimate 486, but with the limitation of being ISA-only... So you can do Am5x86 133MHz, 32MB of RAM. With the PicoGUS, you can use a USB mouse.

No offense intended; I mean this as a legitimate recommendation, but that system really, really needs to have a VLB board.

keenmaster486 wrote on 2026-04-19, 23:18:

Qbccd wrote on 2026-04-19, 21:08:

It's a variation of an ultimate 486, but with the limitation of being ISA-only... So you can do Am5x86 133MHz, 32MB of RAM. With the PicoGUS, you can use a USB mouse.

No offense intended; I mean this as a legitimate recommendation, but that system really, really needs to have a VLB board.

Yeah in the real world the cut off was almost always 50mhz where you didn’t see ISA or EIDE video/CPU upgraded further and the integrated Compaq / HP machines that only had ISA expansion were usually left with whatever came in the case.

Some folks would have an old isa/eisa 486 and started slopping upgrades in there but it was pretty rare as those machines were pretty tapped out by the dx4 era, many had a poor cache (or no cache) setup, 80ns memory, tiny hard drives and no bios upgrade path by that point.

It is sort of interesting to see how much a very high end isa vga would compare to the typical vlb of the era. Some of the exotic stuff was basically the same speed (like cornerstone in windows)

Qbccd wrote on 2026-04-19, 21:18:

I'm also partial to CL because it's what I had as a child. I could never figure out what model though, I know it could do up to 1024x768 (could have been interlaced), but only 256 colors at all resolutions. And it wasn't a CL-GD5420 because it was from 1990-91 and it was a high-end card at the time that my dad bought for publishing work.

Perhaps it was 512K video RAM and not the particular Cirrus chip limiting you to 256 colors.
I think everyone has got the point across that this is more of a curious question than a practical one, but it's still interesting.
Perhaps something that will help is that XFree86 (Linux/BSD) users would have had to deal with the raw details so things may be better documented there.
The readmes for Mach32 and Mach64 http://ftp.xfree86.org/pub/XFree86/3.3.6/doc/README.Mach32 http://ftp.xfree86.org/pub/XFree86/3.3.6/doc/README.Mach64 have details on exactly what it takes to achieve 1024x768x16bpp. Note that this still doesn't tell you which modes are interlaced scan.

Your best bet is the Diamond Speedstar64. I still occasionally see these go for $100-$150 on ebay.
There was a huge glut of these in the mid 90s, and a lot of them were still stocked as new in box until around 2010 or so.
2MB cards that use the Mach32 or S3 928 were made in comparatively small numbers.

MikeSG wrote on 2026-04-19, 10:31:

The top three "used" options are all 'Request A Quote'. They may actually be there but don't use a fixed availability on the website. For me the shipping is the same cost as the card though.

I requested a quote. It is completely out of stock. They only offer repair. $300.

Qbccd wrote on 2026-04-19, 21:08:

It's a variation of an ultimate 486, but with the limitation of being ISA-only... So you can do Am5x86 133MHz, 32MB of RAM. With the PicoGUS, you can use a USB mouse.

If you want the ultimate ISA-only 486, then you need Mach64 or some TIGA, with 4 MB of video memory.
Yes, prices can be prohibitive - but in case of TIGA, you may actually be lucky, such cards are pretty much useless for gaming, therefore they don't get that much love...

are there even win95 drivers for tiga?

rasz_pl wrote on 2026-04-20, 04:21:

are there even win95 drivers for tiga?

I think not.
But some Windows 3.1 drivers can work with the 95, so perhaps there's a chance?

dionb wrote on 2026-04-19, 21:47:

Doesn't do VRAM though, only DRAM. I don't think any of the Cirrus Logic chips did.

For DOS, VRAM actually performs worse than DRAM, but here we're talking Windows acceleration and that's where dual-ported VRAM shines. As for an ISA card with 2MB of it... now that's a challenge.

We can have very theoretical discussions about what would be best in a hypothetical situation where we can get our hands on any given card, but realistically, "whichever one you can find for an acceptable price" would be my suggestion. The already mentioned ATi Graphics Ultra Pro (=Mach32 chip) would probably be best-known, but I suspect that various S3 928-based cards might be more common, things like the Diamond Stealth Pro, Spea/Video 7 Mercury or Mercury Pro (with 4MB...) or the Miro miroCrystal 24S ISA. The only ISA card with 2MB VRAM I personally came across was an Artist Graphics Winsprint 1000, a much more obscure card and chipset (Artist's own GA123), with the added curiosity of a 72p SIMM slot for extra DRAM for the graphics processor. It has Win9x drivers - but sadly my card was dead.

DRAM is fine honestly. I don't need the best Windows acceleration, just some. The main thing I care about is the resolution/color depth. In this regard, 4MB would be unnecessary (and very difficult to find), as I don't think any ISA cards could do higher than 1024x768 at 16-bit, correct me if I'm wrong. So I'm perfectly happy with any of the 2MB cards mentioned, but I'm partial to the CL-GD5434.

keenmaster486 wrote on 2026-04-19, 23:18:

No offense intended; I mean this as a legitimate recommendation, but that system really, really needs to have a VLB board.

Well it's not really a practical/balanced build, it's a nostalgia fun project. My childhood PC didn't have VLB, and my "rule" is that I can't upgrade the board, otherwise it's a like a totally different PC. But the rest is fair game. I'm getting all the original parts as best I can find/remember. (Asus ISA-486 board, 486DX-33, 8MB FPM, probably CL-GD5402 SVGA). I actually still have the original CPU. But I also want to have a maxed out config that can play some mid-90s 2D Windows games, and have nice colors at 1024x768 in the desktop.

jakethompson1 wrote on 2026-04-20, 00:43:

Perhaps it was 512K video RAM and not the particular Cirrus chip limiting you to 256 colors. I think everyone has got the point […]
Show full quote

Perhaps it was 512K video RAM and not the particular Cirrus chip limiting you to 256 colors.
I think everyone has got the point across that this is more of a curious question than a practical one, but it's still interesting.
Perhaps something that will help is that XFree86 (Linux/BSD) users would have had to deal with the raw details so things may be better documented there.
The readmes for Mach32 and Mach64 http://ftp.xfree86.org/pub/XFree86/3.3.6/doc/README.Mach32 http://ftp.xfree86.org/pub/XFree86/3.3.6/doc/README.Mach64 have details on exactly what it takes to achieve 1024x768x16bpp. Note that this still doesn't tell you which modes are interlaced scan.

You're right about this. I must be misremembering something, because I remember it being 1) Cirrus Logic 2) From 1990-91 2) Being able to do 1024x768 at 256 colors. And that doesn't exist from what I've been able to find. So it was most likely 512k of memory and 1024x768 at 16 colors, of which there is one model based on my research - CL-GD5402. So this was probably it, but can never know for sure.

Anonymous Coward wrote on 2026-04-20, 01:22:

Your best bet is the Diamond Speedstar64. I still occasionally see these go for $100-$150 on ebay.
There was a huge glut of these in the mid 90s, and a lot of them were still stocked as new in box until around 2010 or so.
2MB cards that use the Mach32 or S3 928 were made in comparatively small numbers.

Yes, this is the ideal card. Thanks, that gives me hope. Just have to wait for an opportunity then, I thought they were quite a bit more expensive now. The Mach32/64 seem more expensive for sure, but that's my second choice anyway.

With bitblit accelerated cards ram is not as simple as multiplying resolution by color depth. Those cards cant do master DMA from RAM, they bitblit from video ram to video ram meaning you also need space for resources (fonts, graphical elements, whole windows). This is why 4MB cards were made in the first place.

Qbccd wrote on 2026-04-20, 09:01:

I don't think any ISA cards could do higher than 1024x768 at 16-bit, correct me if I'm wrong.

TIGA cards with 4 MB VRAM can do higher, see eg. Miro Tiger:

I must be misremembering something, because I remember it being 1) Cirrus Logic 2) From 1990-91 2) Being able to do 1024x768 at 256 colors. And that doesn't exist from what I've been able to find. So it was most likely 512k of memory and 1024x768 at 16 colors, of which there is one model based on my research - CL-GD5402. So this was probably it, but can never know for sure.

In 1991, CL-GD5402 chips didn't exist.
They were originally released as Acumos AVGA2, and rebranded to CL-GD5402 around 9230..9234:
https://forum.vcfed.org/index.php?threads/acu … t-market.67499/

There's 3x Artist Graphics Winsprint 1000 boards (2MB VRAM) on ebay for $180 USD ono. https://www.ebay.com.au/itm/135074667560

The CL GD5434's are rarely <$150... there was an auction a week or so ago for that amount but very rare. They're $300+ USD cards.

The Matrox Impression Plus 220 is another 2MB VRAM card, but they're rarer still.

bare chips and pci variants are ~$20 and there is this https://github.com/Leshak-pcb/Pine-CL-GD5434 Newly made ISA CL-GD5434

rasz_pl wrote on 2026-04-20, 13:10:

bare chips and pci variants are ~$20 and there is this https://github.com/Leshak-pcb/Pine-CL-GD5434 Newly made ISA CL-GD5434

I had several “Pine” branded components in old 286/386 machines.

When did those stop being a concern?

I looked for history and only found a familiar name as the founder but no dates.

Grzyb wrote on 2026-04-20, 11:42:

TIGA cards with 4 MB VRAM can do higher, see eg. Miro Tiger:

Interesting. Can the ISA bus even properly handle the bandwidth requirement of 1280x1024 at 16-bit? Seems that anything fast-paced would be an issue. Is this the only card that can do this over ISA? It's interesting, but probably impossible to get, and I want something more mainstream.

Grzyb wrote on 2026-04-20, 11:42:

In 1991, CL-GD5402 chips didn't exist.
They were originally released as Acumos AVGA2, and rebranded to CL-GD5402 around 9230..9234:
https://forum.vcfed.org/index.php?threads/acu … t-market.67499/

Oh interesting. What I remember is that BIOS info appearing at the top of the screen during POST, and it definitely said Cirrus Logic and 1991. That's burned into my memory. Maybe it's possible it was an Acumos and it had the CL BIOS message too? Acumos is not a word I ever saw anywhere, at least I don't remember it. I didn't look at the actual card at the time, did not know enough. If it wasn't this one, I really don't know what it could have been. Maybe it was from 1992 after all, but I'm fairly certain the PC was built in 90 or 91 and the video card was never upgraded.

MikeSG wrote on 2026-04-20, 13:06:

The CL GD5434's are rarely <$150... there was an auction a week or so ago for that amount but very rare. They're $300+ USD cards.

The Matrox Impression Plus 220 is another 2MB VRAM card, but they're rarer still.

Yeah... Maybe I'll just get a CL-GD542x for now, and I can periodically look for deals on the GD5434. Where was that auction that you referenced, Ebay?

rasz_pl wrote on 2026-04-20, 13:10:

bare chips and pci variants are ~$20 and there is this https://github.com/Leshak-pcb/Pine-CL-GD5434 Newly made ISA CL-GD5434

Yeah I found that too. It's very cool, but I can't assemble it myself and no one is selling assembled ones. And also I'm not entirely sure I want one. I don't care too much about period accuracy, but this may be pushing it.

Qbccd wrote on 2026-04-20, 21:52:

Interesting. Can the ISA bus even properly handle the bandwidth requirement of 1280x1024 at 16-bit? Seems that anything fast-paced would be an issue.

The idea behind TIGA was: avoid pushing stuff through ISA by keeping everything graphics-related on the card itself.
Such cards were basically separate computers: processor, sometimes also FPU, video memory (up to 4 MB), and separate memory for graphics code and data (up to 8 MB).
Mad-expensive, nevertheless gained some popularity among CAD users.

Is this the only card that can do this over ISA?

There's also ATI Mach64, and S3 Vision928 cards with 4 MB:
https://retronn.de/imports/hwgal/hw_graphics_ … ry_pro_isa.html
http://old.vgamuseum.info/pirxs-collection/15 … nner2000-4.html

Interesting. Can the ISA bus even properly handle the bandwidth requirement of 1280x1024 at 16-bit? Seems that anything fast-paced would be an issue. Is this the only card that can do this over ISA? It's interesting, but probably impossible to get, and I want something more mainstream.

No, ISA is much too slow for 1280x1024 in hi colour. I have a Mach64 ISA with 4MB and it can also do 1280x1024@16-bit....maybe even 24-bit I forget. 1024x768 @16bit is pretty much the limit for desktop use. I would argue the 2MB expansion module on this card is basically useless.

*edit* I checked the user manual. Apparently Mach64 ISA can do 1280x1024 in 24 bit, but only at 60Hz. There was a version of the mach64 cards called the Graphics Pro Turbo 1600 that could do it at higher refresh rates, but that card was only for PCI bus.

Anonymous Coward wrote on 2026-04-21, 01:59:

Interesting. Can the ISA bus even properly handle the bandwidth requirement of 1280x1024 at 16-bit? Seems that anything fast-paced would be an issue. Is this the only card that can do this over ISA? It's interesting, but probably impossible to get, and I want something more mainstream.

No, ISA is much too slow for 1280x1024 in hi colour. I have a Mach64 ISA with 4MB and it can also do 1280x1024@16-bit....maybe even 24-bit I forget. 1024x768 @16bit is pretty much the limit for desktop use. I would argue the 2MB expansion module on this card is basically useless.

*edit* I checked the user manual. Apparently Mach64 ISA can do 1280x1024 in 24 bit, but only at 60Hz. There was a version of the mach64 cards called the Graphics Pro Turbo 1600 that could do it at higher refresh rates, but that card was only for PCI bus.

So I'm curious, what issues would you have for desktop use at 1280x1024@16-bit hypothetically, how would the bandwidth bottleneck manifest? Let's say you changed backgrounds in Windows quickly?

Well 60 Hz is enough for an LCD.

Qbccd wrote on 2026-04-21, 02:18:

Anonymous Coward wrote on 2026-04-21, 01:59:

Interesting. Can the ISA bus even properly handle the bandwidth requirement of 1280x1024 at 16-bit? Seems that anything fast-paced would be an issue. Is this the only card that can do this over ISA? It's interesting, but probably impossible to get, and I want something more mainstream.

No, ISA is much too slow for 1280x1024 in hi colour. I have a Mach64 ISA with 4MB and it can also do 1280x1024@16-bit....maybe even 24-bit I forget. 1024x768 @16bit is pretty much the limit for desktop use. I would argue the 2MB expansion module on this card is basically useless.

*edit* I checked the user manual. Apparently Mach64 ISA can do 1280x1024 in 24 bit, but only at 60Hz. There was a version of the mach64 cards called the Graphics Pro Turbo 1600 that could do it at higher refresh rates, but that card was only for PCI bus.

So I'm curious, what issues would you have for desktop use at 1280x1024@16-bit hypothetically, how would the bandwidth bottleneck manifest? Let's say you changed backgrounds in Windows quickly?

Well 60 Hz is enough for an LCD.

I’ve run 16 bit color at 1600x1200 on a fixed freq workstation card via isa, all I remember is that screen refreshes were very slow and bitmap images could be watched drawing.

The card could accelerate windows and applications moving around and it seems text and line art.

But new stuff you could watch draw across the screen line by line

dionb wrote on 2026-04-19, 21:47:

For DOS, VRAM actually performs worse than DRAM

Funny how I've seen that mentioned several times, yet nobody can provide evidence to that claim.

Meanwhile, back in reality:
Re: Wow ISA BUS insanely overclocked and running DOOM at 35 FPS with an ISA ATI Mach32

EDIT: oh hey, I also have some benchmarks of PCI DRAM and VRAM mach32 that I did with a GA-5AX and an AMD K6-3+ at 100*6 FSB. Damn, how does the DRAM keep losing (except for EGA performance)?