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PCEm. Another PC emulator.

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Reply 1020 of 1034, by SarahWalker

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kekko wrote:
Hi, I gave a look at this after quite some time, and I must say it's coming together very nicely. Rock stable, lot of hardware […]
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Hi,
I gave a look at this after quite some time, and I must say it's coming together very nicely.
Rock stable, lot of hardware is emulated, user friendly interface..
I got few questions, but I couldn't register on the official forums.

Sorry, was away for a few days. You should be approved now.

I can't find a regularly updated repository; it's not maintained anymore?

https://bitbucket.org/pcem_emulator/pcem

Any plans for new gpus?
I'd like to see the mga g200 (specs) emulated and even thought of working on it myself in my spare time. Well, I would like to 😀

You'd need to reverse engineer the Warp Engine for G200; Matrox never publically released documentation.

Reply 1021 of 1034, by kekko

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Yep. I actually thought that if I ever worked on it, it would not provide a software rasterizer at all.
But, for me, it was just to get a better directx support than voodoo, not for emulating the g200 accurately.
I can understand it's not the scope of this project.

Reply 1022 of 1034, by leileilol

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Yeah PCem's all for getting the target performance right. Offloading 3d to hardware would bring far too much inaccurate representation, external variables of potential unstability (GPU drivers) and fantasy speed. There's also been many similar requests for virtualization that also would have the same not-the-scope issues. Also I prefer accuracy too, all of the quirky 'trademark' imperfections must be preserved. Voodoos must blur, Virges must overdraw their dither, etc..

All I can think of for your "better directx support than Voodoo" is the Voodoo emulation expanding to Banshee, which would help compatibility with D3D/GL (allowing it to run maybe a few more 2001 games), drive 3D in WinNT, and have better execution for supporting resolutions below 512x384 😀

Though if PCem does go down this VB/V3 path (I don't know if it will) i'd have to reverse that '22-bit' 2x2 box filter, and also (according to the datasheets) the filters are applied in a variable region rather than the whole screen - both of which might not work well with the threaded rendering.

by the way, DOSBox is not for running Windows 9x

Reply 1024 of 1034, by Doomn00b

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appiah4 wrote:

Are there any decent forks of this project?

There sure is! : ) 86box is the most notable one. It's a bit more experimental though, so be aware that it's often not quite as stable.

Reply 1025 of 1034, by kekko

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I agree with getting accurate emulation with cards like the 3dfx, which featured 16-bit color renderer and dithering.
D3D cards from the G200 era onwards, on the other hand, featured 32bit color renderers not much different from what you will get by just forwarding triangle calls to an opengl backend, in an emulator.
Banshee cards might be a partial solution, but they're still limited to 16-bit color, and voodoo in general were not designed with D3D in mind.
From my point of view there is an area still not covered by emulators, which is D3D gpus in the 1998-2001 timeframe; everything else, from 1981 to 1997 is already covered I guess..

Reply 1026 of 1034, by kekko

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SarahWalker wrote:

You'd need to reverse engineer the Warp Engine for G200; Matrox never publically released documentation.

From what I got from driver sources and from this specification, it looks like there are few fixed pipelines for basic rasterizers:

For optimum performance, more then one pipe is provided to minimize unneeded computations.  Those pipes are TGZ, TGZS, TGZA, TGZF, TGZSA, TGZSF, TGZAF, TGZSAF, T2GZ, T2GZS, T2GZA, T2GZF, T2GZSA, T2GZSF, T2GZAF and T2GZSAF.
Where:
T stands for computation for texture stage 0.
T2 stands for computation of both texture stage 0 and texture stage 1.
G stands for computation for triangle intensity (Gouraud interpolation).
Z stands for computation for Z buffer interpolation.
S stands for computation of specular highlight.
A stands for computation of the alpha channel.
F stands for computation of the vertex fog interpolation.

Maybe these might be directly mapped to fixed pipelines in the emulator.
I expect not many games actually run specific microcode.
I am interested in your opinion on this 😀

Reply 1027 of 1034, by ElBrunzy

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I was wondering if pcem could help me debug s3 virge pci bios and fix vbe 2.0 and vbe 1.0 bios blank problem. I'm searching on a way to edit live vga bios.

Reply 1028 of 1034, by Battler

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Doomn00b wrote:
appiah4 wrote:

Are there any decent forks of this project?

There sure is! : ) 86box is the most notable one. It's a bit more experimental though, so be aware that it's often not quite as stable.

That was maybe true in the beginning, but noawadays, if anything, 86Box has stricter requirements for what is added than PCem does. Though of course, there's still bugs and imperfectly emulated hardware inside.

Reply 1029 of 1034, by kruwi

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I have tried out PCEM and am fairly impressed. My quite crappy laptop (Pentium Silver N5000) manages to emulate a Pentium 90 at full speed (between 99-101 percent, very rarely dropping to 97 percent). I have also tried out a Pentium 100 and a Pentium 133, but a Pentium 90 seems to be the reasonable limit the host cpu can emulate on my system. I expected the performance to be worse, though and am quite pleased 😉. Running Windows 95 (P90) and Dos 6.22 (486 DX2 66).

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Reply 1030 of 1034, by jesolo

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kruwi wrote on 2020-01-09, 19:08:

I have tried out PCEM and am fairly impressed. My quite crappy laptop (Pentium Silver N5000) manages to emulate a Pentium 90 at full speed (between 99-101 percent, very rarely dropping to 97 percent). I have also tried out a Pentium 100 and a Pentium 133, but a Pentium 90 seems to be the reasonable limit the host cpu can emulate on my system. I expected the performance to be worse, though and am quite pleased 😉. Running Windows 95 (P90) and Dos 6.22 (486 DX2 66).

I've also tried out PCem and I'm also impressed by its emulation of the real hardware.
I'm fortunate enough to own a range of vintage hardware so I don't actually use PCem that often but, I can definitely recommend it as another alternative to some other great emulators out there.
I do sometimes use PCem to test out different configurations or different types of software (since it's much quicker to swop out disk images as opposed to swopping out real floppy disks 😊).

Reply 1031 of 1034, by Jo22

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I'm also impressed by 86Box/PCem and I think there is still a lot of room for improvement also.
Like FPU or serial port support, just to name two examples that come to mind.
(And last but not least, V20/V30/186 support for XT machine types, heh. 😉 )

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

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Reply 1032 of 1034, by Tertz

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kruwi wrote on 2020-01-09, 19:08:

I have tried out PCEM and am fairly impressed. My quite crappy laptop (Pentium Silver N5000) manages to emulate a Pentium 90 at full speed (between 99-101 percent, very rarely dropping to 97 percent)

I suspect DOSBox allows x2 times faster emulation. Mb useful for late 3D DOS games.

DOSBox CPU Benchmark
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Reply 1033 of 1034, by Jo22

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Tertz wrote on 2020-02-10, 19:39:
kruwi wrote on 2020-01-09, 19:08:

I have tried out PCEM and am fairly impressed. My quite crappy laptop (Pentium Silver N5000) manages to emulate a Pentium 90 at full speed (between 99-101 percent, very rarely dropping to 97 percent)

I suspect DOSBox allows x2 times faster emulation. Mb useful for late 3D DOS games.

I second that. I managed to get near Pentium speed in DOSBox (an old unofficial CVS build) on an Athlon 64 X2 PC.
At the same PC, PCem managed to emulate a 486DX-50 at max. Still, that's remarkable also, I think.
Screenshot & Configuration -> Re: A problem when trying to install a Living books game on Windows 3.1 on PCem.

Edit: I did forget.. I have to add that this speed was archived without the dynarec.
If it's now working without causing stability issues in WfW 3.11, things might be notable quicker even. 😀

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//