DOSBox treats every instruction as one cycle. PCem does not.

awgamer wrote:

but roughly..
dosbox
xt@4.77 ~= 253 cycles

For DOSBox. According to MIPS GI param wich is better for games than general rating there and how games work on practice - 310 is closer to correct. 253 is a bit laggy.

> at@6 ~= 552 cycles

286 6 MHz was ~3 times faster than XT 4.7. Look at official MIPS for those CPU and what benchmarks show. So AT 6 MHz is about 1300 in DOSBox. Note: not any benchmark give results adequate to gaming performance in DOSBox, so in some you get bullshit like in TOPBench's general index and hence may be leaded to too incorrect cycles setting.

> 386@25 ~= 4700
> 486@66 ~= 23300
> 586@133 ~= 70600

386DX 25 - 5900
486 66 - 26800
Pentium 133 - 100000 cycles

My results are according to Speed Test. Its results give good correlation with Doom 1.9 performance in DOSBox what you may check by Phil's testing. In what games were checked your results stays unknown, at least they are not crtitically far except 286 CPU. And also switching sound on in games may need more cycles for same performance.
Would be good if there were ways to measure in numbers the performance in any games (Commander Keen, etc), similarly as Fraps does in Windows. Something like GameWizard, but with this possibility. Then we'd have way to tune performance in any game close to level of any cpu, - this may be fun. As for now, good to find more pre-1995 games with internal benchmarks to check cycles correlation than Doom and World Circuit, desirable not only 3D games.

leileilol wrote:

DOSBox treats every instruction as one cycle. PCem does not.

THIS.

News that PCem project has been uploaded to bitbucket.org. This is welcome news, especially since the web site allows a more friendly environment for developers. Branches may be created for open source projects, members may collaborate, and then developers can save space/commit annotations by deleting the branches after adding only the code to the main trunk. This is appealing because it allows open source project owners to have full ownership of their projects. Other web site tools are nearer to the philosophy where changes are made exclusively through the use of project forks, but some disagree with this open arrangement of development.

Other developer-friendly strategies includes the addition of large libraries to a project, making the code difficult to follow (the subdiscipline of obfuscation), and bundling a project with a single set of development tools. These will prevent project forks and others from interfering with mainline code.

Any interest in Cyrix M1/MX/M2 emulation? I made a naive-as-hell Pentium-based fake Cyrix patch that has some Cyrix timings implemented (implementing clock cycles from some pdfs in a non-opcode order is tedious). It's way off the 686 benchmark results here though and I'm not really a CPU coder to go further. The only emulator I think of that emulates these things is MAME's MediaGX code.

I don't want to read (nearly) a thousand messages, but here's this...

https://github.com/OBattler/PCem-X

It's said to offer certain additions such as better floppy emulation.

And it uses GitHub for code. BitBucket interface is in the past too and Atlassian isn't less evil than GitHub, they have even more proprietary software. A better choose would be GitLab. It seems he loves mercurial, despite Git is even replacing to Microsoft tools too 😁

https://bitbucket.org/pcem_emulator/pcem/commits/all

PCem-X is obsolete and mainline PCem has much better floppy emulation than PCem-X now.

Battler wrote:

PCem-X is obsolete and mainline PCem has much better floppy emulation than PCem-X now.

Are there any features mainline PCem still lacks in comparison to PCem-X?

Forcing the emulated screen to 4:3 (much like a real CRT would do), improved CGA emulation, keyboard improvements, a few emulated machines, just to name a few.

I tried the PCem Linux version, couldn't figure out where it wanted its ROMs to be put, so I resorted to running the Windows version in WINE. 🤣 Where does the Linux version look for its ROMs? If it makes any difference, I installed it from the AUR on Manjaro 16.06.

in the roms folder.

leileilol wrote:

in the roms folder.

But where would I find the roms folder?

in the PCem folder.

Also don't forget to read the readme to find rom filename hints. If you're looking for Pentium Win98 3dfxing just grab a S3 Trio64 or Virge/gx rom and the specified Award 430vx rom (which is the easiest motherboard to work with currently). You could also dump your own rom (and clip off for just the first 64kb of an s3 for instance - i use my own s3 and awe rom dumps)

Also i've been making videos.

I have read some things on the web concerning the usefulness of this emulator. I just wanted to chime in and let everyone that has been working on this project know that this is a really big deal for me and I truly appreciate the development. I have one heck of a big collection of games from 1996 to 2000 that DO NOT run very well, if at all on DosBox. DosBox does what it does well and handles the rest of my collection of classic games. I am taking no shots at DosBox here. PCEm can fill a huge gap IMO and the latest version has already shown a lot of success. I hope soon I can just unplug my old Dell GX150 with the Voodoo2 card and pack it away. That extra clutter around the desk is a pain.
Anyway...I just wanted to say Thank you for the great work. I hope to start putting some demo videos up on Youtube showing some of the games running on PCEm that I have only been able to run on my old Dell. I-76, Janes Longbow 2 and others..

v11 is now out. Changes since v10.1 :

• New machines added - Tandy 1000HX, Tandy 1000SL/2, Award 286 clone, IBM PS/1 model 2121
• New graphics card - Hercules InColor
• 3DFX recompiler - 2-4x speedup over previous emulation
• Added Cyrix 6x86 emulation
• Some optimisations to dynamic recompiler - typically around 10-15% improvement over v10, more when MMX used
• Fixed broken 8088/8086 timing
• Fixes to Mach64 and ViRGE 2D blitters
• XT machines can now have less than 640kb RAM
• Added IBM PS/1 audio card emulation
• Added Adlib Gold surround module emulation
• Fixes to PCjr/Tandy PSG emulation
• GUS now in stereo
• Numerous FDC changes - more drive types, FIFO emulation, better support of XDF images, better FDI support
• CD-ROM changes - CD-ROM IDE channel now configurable, improved disc change handling, better volume control support
• Now directly supports .ISO format for CD-ROM emulation
• Fixed crash when using Direct3D output on Intel HD graphics
• Various other fixes

As ever, it's at http://pcem-emulator.co.uk/

I just can't make this thing work.

I made a configuration (286 AT, 1MB RAM, EGA), loaded DOS 6.22 and the best i could get is a "loading MS-DOS" message that seems stuck, unless it really does load for so long (i have left it there for 20 minutes). I don't have experience with old DOS computers but i think this isn't how it's supposed to be?

SarahWalker wrote:

v11 is now out. Changes since v10.1

Amazing work, Sarah. 😀

fwfa wrote:

I have one heck of a big collection of games from 1996 to 2000 that DO NOT run very well, if at all on DosBox.

What games? If they're DOS games, and there's some broken/missing feature stopping them from running in DOSBox, I'm sure the devs would like to know! 😊

SquallStrife

I am at work right this second so I do not have the answer right now...but my two biggest issues were I76 and Longbow 2. I did get both of these working with no special prep under Windows 98SE installed on PCEM. Oddly enough, I also found out that some people had finally gotten the same games working on Windows 7 around the same time. I followed the instructions and both of them now work under Windows 7.
Most of the games I am concerned about are right in the sweet spot between Dos and pure Windows ME. I believe I have a good many Novalogic games and others that I have had trouble with.. In the end I put together an old Dell PC with a VooDoo 2 card and windows 98 to get the games running correctly.(no random crashing) It does drive you a little nuts taking up all that real estate under your desk for another machine. I will do as you suggested and push the problems out and see what I get back. Thanks for the reply.

Oh, so Windows games, not DOS games?

Yeah that's not surprising then, PCem is better for that for sure.