It's a bit of an odd pairing.

You are better off looking for an SBC with built in graphics. There are plenty of models with VLB or PCI VGA chips onboard. That would be a better option than a PPro and ISA VGA, plus only use a single (ISA) slot.

i already have a sbc with socket 370, But pentium Pro is very nice to have, thats why i ask about isa vga.

Short answer is yes, don't even bother.

keenmaster486 wrote on 2024-05-31, 20:32:

Short answer is yes, don't even bother.

sorry non understand what you mean

I wouldn't bother with a Pentium Pro if the main intent is DOS gaming. And certainly not if the only option is an ISA video card.

Such a setup would be a waste of its capabilities.

ok, i let it go. i keep my sbc socket 370

Are there dos games that really need more than isa can offer?

Can’t a gd5434 basically play any dos game out there? Or did I misunderstand something?

Of course, the limiting factor here is the isa gpu. But dos stuff didn’t need much of a gpu. It wasn’t until windows gaming that you started needing actual 3d accelerators.

The pentium pro is for sure wasted on such a setup, but so is the 370.

I’m a little curious for pics of this proposed project, is OP using an existing mobo as a backplane? Or retrofitting a backplane into this Amiga?

These were indeed my doubts. What if an ISA video card (the one with the fastest chip) was too crippled by the ISA bus. My choice on the Pentium Pro was solely for a historical and non-functional collecting reason, I understand very well that an sbc with a Pentium MMX is the best choice, but I wasn't looking for the best choice, I was only asking if the Pentium Pro + ISA VGA combination works fine in DOS games. I chose an Amiga 2000 (in the holiday home) because in addition to being able to use all the wonderful Amiga playground, it already has 4 slots inside and can be integrated onto the motherboard which at the time was used for compatibility with the IBM PC world via the bridgeboard and which can now be used as a convenient integrated backplain.

It would work. But ISA bus makes a big performance hit. But it also depends on the game. Some are not very "bus" intensive.

ISA is fine for typical 320x200 games (that's 320x200 pixels, by 1 byte per pixel, for a high refresh game like Doom lets say 30fps = just shy of 2mbytes/sec), but anything 640x400 (four times the bandwidth of 320x200 at the same frame rate) or above is going to have it's performance crippled by anything less than VLB.

I don't know why you would need the speed of a 200MHz processor for 99.9% of 320x200 gaming... So yes, I would say a PPro 200 (or indeed a regular P200) with an ISA video card would indeed be a waste.

IMHO a working PPro MB or Amiga 2000 worth a lot more than, say, a generic PCI graphics card (e.g. S3 Trio series) plus a used case. Why not just pair the PPro with its own case and contemporary graphics instead of squeezing it into an Amiga case designed for Motorola 68K?

What SBC are we talking about here? Is it ISA only, or is it a PICMG card, with PCI connector in front of the ISA connector?

dormcat wrote on 2024-06-01, 10:27:

IMHO a working PPro MB or Amiga 2000 worth a lot more than, say, a generic PCI graphics card (e.g. S3 Trio series) plus a used case. Why not just pair the PPro with its own case and contemporary graphics instead of squeezing it into an Amiga case designed for Motorola 68K?

basically to have just ONE desktop with 2 system inside. I not want to fill my holiday house with PC, like my all-day house. Just this.

CL GD5434 on ISA is almost as fast as the slowest PCI cards, so quake would be playable within 1990s expectations, not "my eyes bleed if it's not 4k and 120fps" expectations.

dionb wrote on 2024-06-01, 11:30:

What SBC are we talking about here? Is it ISA only, or is it a PICMG card, with PCI connector in front of the ISA connector?

is whit isa and pci in line.

What perhaps I failed to make clear is that I'm not looking for just any sbc for any backplain. But it must necessarily reside inside the Amiga 2000 which has 4 isa slots that work as a backplain (I currently have an sbc with socket 370 and alongside it a Sound blaster 16 which work very well). What I would have liked is the cool-factor of the Pentium Pro.

AlessandroB wrote on 2024-05-31, 19:52:

I can find a nice SBC with Pentium Pro 200 to fit in my amiga 2000, the inly problem is that the only graphic card i can fir will be a ISA card… that make the Pentium Pro inusable in mid DOS gaming??

Not unusable for DOS gaming but the experience isn't ideal because of the bottleneck of an ISA video card (especially with SVGA/VESA video modes) and performance hit that the Pentium Pro has with 16-bit and mixed codes where partial registers usage are common.

i must point that my golden era is the DX2 period.. is nice to have a computera than go beyond the dx2. the only problem i see is that my prtojecct can be more expensive than i supposed

megatron-uk wrote on 2024-06-01, 10:05:

ISA is fine for typical 320x200 games (that's 320x200 pixels, by 1 byte per pixel, for a high refresh game like Doom lets say 30fps = just shy of 2mbytes/sec), but anything 640x400 (four times the bandwidth of 320x200 at the same frame rate) or above is going to have it's performance crippled by anything less than VLB.

I don't know why you would need the speed of a 200MHz processor for 99.9% of 320x200 gaming... So yes, I would say a PPro 200 (or indeed a regular P200) with an ISA video card would indeed be a waste.

Man, with a isa card you cant even play doom at good framerate

Tested one day for fun,a 233mmx+isa is much slower at doom than a dx2 66 with vlb

megatron-uk wrote on 2024-06-01, 10:05:

ISA is fine for typical 320x200 games (that's 320x200 pixels, by 1 byte per pixel, for a high refresh game like Doom lets say 30fps = just shy of 2mbytes/sec), but anything 640x400 (four times the bandwidth of 320x200 at the same frame rate) or above is going to have it's performance crippled by anything less than VLB.

I don't know why you would need the speed of a 200MHz processor for 99.9% of 320x200 gaming... So yes, I would say a PPro 200 (or indeed a regular P200) with an ISA video card would indeed be a waste.

ISA is also fine for 800x600 SVGA in graphics adventures and flight simulators.
Or rather, it's the only option. For early titles, I mean.

Pre-VBE games are chipset dependent.
MS Flight Simulator 4 supports 800x600 graphics for ET4000/ET4000AX, but not ET4000/w32.

The Legend Entertainment games like Gateway I&II or the Spellcasting series support ET4000/ET4000AX only, it seems.

Some of the later Magnetic Scrolling games (Wonderland and The Magnetic Scrolls Collection, Volume 1) , with the new windowing system (Magnetic Window) do support Paradiese PVGA/Western Digital WD90Cxx and the Video Seven VEGA series.

These are all humble ISA cards, no PCI and VLB.

I often thought about building a 586 build in the future, with both an ET4000AX and Voodoo 1 card being installed, to cover many classics.

The ET4000AX can technically run on a slightly overclocked ISA bus, but the ISA-PCI bridge would still affect latency, I suppose.

That being said, it just came to mind when reading the thread.
Only a few people would play such niche games, anyway, especially in SVGA. Normal VGA resolution works on any VGA card.
The Magjetic Window engine can be patched for using VBE mode, at least, also.

Edit: Technically, it's all about VGA BIOS and video modes, rather that the underlying graphics hardware. 800x600 16c typically uses same memory layout as 640x480 16c, also.
But I'm not sure how far some applications/games go when checking for a supported SVGA mode, whether or not they try to check for a BIOS string or something.