PCem v13.1 is now available. This is a quick bugfix release, with the following changes from v13 :

• Minor recompiler tweak, fixed slowdown in some situations (mainly seen on Windows 9x just after booting)
• Fixed issues with PCJr/Tandy sound on some Sierra games
• Fixed plasma display on Toshiba 3100e
• Fixed handling of configurations with full stops in the name
• Fixed sound output gain when using OpenAL Soft
• Switched to using OpenAL Soft by default

Just trying this out now, I've played with it a little bit previously but never got very far. This new ver seems very solid & much improved from the last one I checked out (v10.x??). Nice job. 😀

Any thoughts on an OS/X port? I'm running it under WINE and it seems to work fine, but always nice to have a native version. I'll try the Linux port on one of my other boxes when I get the chance.

It supposedly can compile for OSX as-is without CD-ROM support (host drive assuming)

Been prototyping an alternate machine configurator that I'd find more interesting to use than the text-based gui. In essence a 3d retro pc builder, you drag components/parts off a list onto suitable connectors on the stuff already installed, with dynamic recursion of expansion, e.g. motherboard - riser - video card - vram chips. At the end, the program would spit out a pcem-compatible config file based on the installed parts, and tell pcem to run the machine. Gives a more tangible feeling of operating an old pc than what the text gui can, but in many ways isn't as convenient/easy.

You could expand on this somewhat uselessly but coolly by adding a monitor object into the configurator and having pcem's output be rendered onto its screen. Then you begin slowly approaching a 'my summer car' type thing of retro pcs.

Hopefully you can do the same with all the jumper settings to set multipliers and sound card IRQ/DMAs, and recreate physical IDE ribbon hell 😀

I'd probably try attempting modeling the parts as well, though i'm only really good with organics and less so on rigid hard edged stuff...

PCem would also need a special GL3 renderer driver for that (or maybe simply a shader that somehow imports geometry and dumps the pcem screen onto the 3d monitor's surface, complete with per-pixel lighting and screenspace reflections of the screen contents, along with moving the sound sources of the pc speaker into the physical 3d space of the case and other silly futureproofing for VR)

It's being built to my spec, so unfortunately that means software rendering, low-poly models and low-res textures. It's all in the mind.

That's...awesome!

I got interested in testing the monitor thing. You can hack a kludge with linux's 'import' tool to rip the pcem window's output onto disk and from there into a texture buffer in the program, mapped onto a monitor's 3d model. https://www.youtube.com/watch?v=3CwUyrflkbE

The video degrades the image quality and the framerate suffers massively from having to route pcem's output, but the effect can be evaluated. It's kinda cool, more a novelty though than a necessity. Would be better if the motherboard on the left had the proper components installed and not some random unfinished models. Add a vga cable snaking along there as well and it'd be cool I guess. It's also kinda cool by the way how you get an automatic 4:3 (or so) aspect ratio when you map the output texture onto the monitor's screen mesh.

I made a Windows 95 setup + Voodoo 2 to try a game but i can't get this to work.

I'm trying to play Star Wars Episode 1 Racing and i'm getting a message that there is no 3D device configured. I'm running the DXDIAG tool and i get a "no acceleration available" in either cards (the default card and the Voodoo 2). And yet in the monitor properties i can see the Voodoo 2 settings and even the classic 3DFX logo. I installed the drivers successfully but i still get this message. I know that the game probably uses Direct 3D and no Glide. But i thought it would run fine on a Voodoo 2.

What am i doing wrong?

Make sure you have both DirectX6.1 installed and an appropriately old driver (i.e. the Voodoo2 DX7 driver from Nov 99 and after (as well as all those fan drivers) won't work with Dx6 installed), or have DirectX 7 (or better) installed with a Voodoo2 DX7 driver.

Racer does work.

I already had direct X 6.1 (it was included in the game) so i assume the Voodoo drivers were wrong.

Installing direct X 7 and compatible Voodoo drivers did the trick.

The game runs at full speed with a Pentium 200 guest machine (100% emulated speed on a i5 4670 host). There is a lot of sound lag and other issues with sound. But i read that it's a known issue with Pcem.

Thanks for the help.

Memory sharing (shm on linux, don't know about windows) pcem's output pixel buffer to the external renderer works in about realtime (sans thread safety). https://www.youtube.com/watch?v=vTO_a9gLhSE. Still requires allowing pcem to mouse lock for interaction, but kinda cool anyway.

Anyone know why the PCem forum is down?

DOSfan1994 wrote:

Anyone know why the PCem forum is down?

It's fine for now at least.

http://downforeveryoneorjustme.com/www.pcem-emulator.co.uk

In a version of Warcraft 2 for DOS, PCem's S3 devices lead to squashed video in the emulated screen. Tested with serial mouse (ctmouse) and sbpro sound. This alternate UniVBE VESA driver fixes this issue:
https://web.archive.org/web/20060118061752/ht … dd/univbe67.exe

I read the recent commit for improvements to the video timing. I would like to verify that a S3 video device shows a greater time to read than write to the pci bus.

1video_timing_read_b = (int)(bus_timing * 25);
2video_timing_read_w = (int)(bus_timing * 25);
3video_timing_read_l = (int)(bus_timing * 40);
4video_timing_write_b = (int)(bus_timing * 3);
5video_timing_write_w = (int)(bus_timing * 2);
6video_timing_write_l = (int)(bus_timing * 4);

I provided the benchmark results justifying those changes here : http://pcem-emulator.co.uk/phpBB3/viewtopic.php?f=4&t=877.

Thanks for showing the results.

Also, is it possible to significantly improve the performance of pcem's interpreter cpu core like in dosbox's normal core.

There might be optimisations there. But since PCem has the dynamic recompiler these days, why bother?

I'm using a video card incapable of native dos resolution (is it 320, or 720x400?) but figured I should ask before putting an older card in - will I be able to get the same resolution at fullscreen as I'd get booting into dos?

Also, is there any way to change the refresh rate? I'm using a crt, and regardless of the windows refresh rate, it won't go above 50 or 60hz.