v15 released!

[tk421]

I have finally had the chance to try v15 on a modern laptop. It is a Lenovo laptop using the Intel Core i7 9750H processor. The cpu in question can exceed 4 Ghz, with speeds of 4.15 Ghz not uncommon. From time to time the machine will reach 4.25 ghz. I have seen spurts of 4.33 Ghz, even moments with 4.43 Ghz.

PCem v15 runs ok in a VMware virtual machine running Win XP on this Lenovo laptop. MSI and Acer laptops seem to run PCem within VMWare better than this lenovo machine. First impressions for Intel emulated CPUs are generally favorable.

The AMD K6-2 350 works ok with only a little sputtering sound. Strangely if I change the emulated CPU beyond the K6-2 350, say to 450 or even 500 Mhz, then the emulated win95 PC will not start, but it will give windows protection errors. The K6-III line of emulated CPUs produce the same error on start. Has anyone seen this?

The Intel CPUs I tried in PCem never produce any of these errors, only the high end K6 CPUs seem to be affected. What should I do to fix this error?

[leilei]

Real behavior. Win95 will actually throw protection errors on CPUs that fast! There's a patch for it, but generally it's easier to install Win98 (or better) instead.

[SarahWalker]

I'd forgotten to actually test that, so I'm glad to see the K6 timings are accurate enough to break Win95a.

[tk421]

Thank you.

I am glad PCem provides accurate emulation for these CPUs. I will do my best to fix this Windows Protection Error. If this is not possible, then loading Windows 98 will not be a problem.

[CryptidWorks]

Double-posted on me, Ignore.

[CryptidWorks]

Not a lot for the most part; the main CPU load is the CPU emulation, and that's strictly single threaded. The only reason to go past 4 cores is if you want to emulate a Voodoo 2 SLI setup, as the Voodoo emulation can use up to 3 threads per card.

This disappointing but understandable since it's hard to multi-thread emulation of components that were originally single-threaded.

On another note is there a plan to eventually let the problem use more of the CPU? On mine hang-ups and speed drops can happen even though I'm not even hitting 60% usage on any of the cores. Seems to be caused mostly by the emulator reading data from my optical drive so I'm tempted to try ripping my games to ISOs when I play them in PCEM.

On 2 seperate machines, I have noticed the optical drive will almost surely cause a slowdown. Making ISOs and putting it on the virtual drive is highly recommended.

I dunno why, but using an external virtual drive like PowerISO versus PCEM's gives me better performance, too.

As weird as it sounds, that was 100% right.

I ripped an ISO and directly mounted as an image with PCEM. Now the game runs full-speed with no slow down on the same virtual hardware configuration. I guess reading from system's physical drive isn't totally ironed out yet and causes hitches.

[CryptidWorks]

After ironing things out by using ISOs instead of the discs I've got a Ryzen 3600X with precision boost enabled that hits around 4.3Ghz sustained single core boost and 4.1Ghz all core running Windows 98 games on a Pentium MMX 233Mhz fulls-speed without issue. I also have a Voodoo 2 installed in the virtual system but I haven't tried any 3D accelerated games yet.

[CryptidWorks]

Tested Paintbrawl 2.

It has this weird quirk where only the Glide option works at 640x480 (you have to use 800x600 for the 3D card option to take) but it does remain at 100% speed when running a 3D accelerated game on a Voodoo 2.

However badly this game wants to run on any settings just of it's own accord.

[omarsis81]

Thank you! v15 finally arrived!
One question Sarah: do you have more ideas for further optimisations?

Yes. It's mainly a matter of time and energy, and I don't have any of the latter left at the moment!

Hi Sarah! How are you feeling? It has been many months since the last Commit. I wonder what are you up to?

[SarahWalker]

Having a nice break, getting a couple of long overdue non-PCem projects done. I'll probably get back to PCem in a couple of months or so.

[szadycbr]

Get some rest Sarah You well deserve it and need it

[j1forPandE]

This may be off-topic, but then maybe not. Id like to congratulate you on the release of Arculator 2.0 which has been released a few days ago.

It emulates many Acorn Archimedes systems with very high compatibility. I guess many people in this forum are interested in old computers in general, so go check it out: http://b-em.bbcmicro.com/arculator/

The Archimedes range is particularly interesting, because they are something like the precursors of Raspberry Pie and the descendants of their ARM CPUs are in everybodys mobile phone, etc.