SarahWalker wrote:

SA1988: Great, thanks! Can you PM me the details of what needed fixing? I was already aware of the need for REP NOP, but forgot […]
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SA1988: Great, thanks! Can you PM me the details of what needed fixing? I was already aware of the need for REP NOP, but forgot to check it in with the previous NT fixes.

Before anyone inevitably asks, Windows 2000 is the last version of Windows that will run on the hardware PCem emulates, so there's no point at present in trying to get XP working.

Windows95Fan: I already had this conversation with you several pages ago. I don't want to have it again.

Edit: Hang on, are you Javier Donoso again? In any case, welcome to my ignore list.

Bullshit!!

I remember that conversation, actually. Sarah doesn't work for you, man.

Well, from what I see, we know the fix for this time/date "bug". All that has to be done is for someone to add a configuration setting to PCem which can enable/disable changing the date/time inside the emulated PC. I could try doing that. That way the wolf is not hungry anymore and the sheep is still alive (that's a Slovenian saying, BTW). Those who want to run Beta's then can turn the switch on, while those who don't, can simply keep it at default which will be off.

leileilol wrote:

Aren't final Windows releases 'beta' enough?

Sarah doesn't have to support the fantasies of 'window's beta' kids.

Not everyone who tests old Windows Beta's is a kid. Some of us, like myself and SA1988, for example, do it for the purposes of research and learning how operating systems evolved. So please avoid such disparaging generalizations.

Another saying is that "you can catch more flies with honey than with vinegar". Or perhaps one could submit a "request" to Sarah instead of hassling her.

The triple account owner has had his accounts disabled.

1#define divexcp()

1case 0x90: case 0x190: /*REP NOP*/
2case 0x290: case 0x390: /*REP NOP*/
3oldds=0;
4ds=0;
5changeds=0;
6return;

With these patches, Win2000 can now run fine on the Award 496/497 and Award 430VX.

Okay, I'm going to have to look into Windows 2000 further. Neither of those are fixes I can take - I'd assume that REP 0x90 shouldn't be zeroing DS, and disabling divexcp() will break anything relying on divide exceptions. The latter does at least point at where I should be looking though.

ppgrainbow wrote:

Update: On the side note, as Windows 2000 and Windows Millennium are the last versions of Windows that will work with PCem, Windows XP requires Windows Product Activation for which it won't work at all with PCem. I was lucky enough to get Windows XP installed inside VirtualBox...so, I might even try to install PCem on Windows XP inside VirtualBox! 😀

XP will work in PCEm when it emulates a Pentium class machine well enough. WPA has nothing to do with it. Even when it does, its fairly pointless. PCEm is really about getting older software/OSes running on modern machines and emulating other pieces of period hardware (like video/sound cards).

NJRoadfan wrote:

ppgrainbow wrote:

Update: On the side note, as Windows 2000 and Windows Millennium are the last versions of Windows that will work with PCem, Windows XP requires Windows Product Activation for which it won't work at all with PCem. I was lucky enough to get Windows XP installed inside VirtualBox...so, I might even try to install PCem on Windows XP inside VirtualBox! 😀

XP will work in PCEm when it emulates a Pentium class machine well enough. WPA has nothing to do with it. Even when it does, its fairly pointless. PCEm is really about getting older software/OSes running on modern machines and emulating other pieces of period hardware (like video/sound cards).

Well, the WinChip C6 cpu is a 586-class one, isn't it? Still, WinXP is a bit harder (by now) to emulate on PCem and would be painfully slow as damn, so...

From the WinChip datasheet :

The Pentium processor-compatible CMPXCHG8B instruction is provided and always enabled. However, the default for the corresponding CPUID function bit is 0 (due to a bug found in Windows NT). This default can be changed via a bit in the FCR MSR.

I don't think this is enabled in the BIOS, or by Windows XP, and even if it is I'd assume it'd run into whatever mysterious 'bug' IDT are mentioning here.

NJRoadfan wrote:

ppgrainbow wrote:

Update: On the side note, as Windows 2000 and Windows Millennium are the last versions of Windows that will work with PCem, Windows XP requires Windows Product Activation for which it won't work at all with PCem. I was lucky enough to get Windows XP installed inside VirtualBox...so, I might even try to install PCem on Windows XP inside VirtualBox! 😀

XP will work in PCEm when it emulates a Pentium class machine well enough. WPA has nothing to do with it. Even when it does, its fairly pointless. PCEm is really about getting older software/OSes running on modern machines and emulating other pieces of period hardware (like video/sound cards).

Windows XP will work, but on a original Pentium processor, the RAM would have to be maxed out at 256 MB in order for it to run reliably. And since the original Pentium is below the minimum requirements, the OS would be painfully too slow to navigate and to make matters worse, Windows XP can take up gigabytes of disk space with all of the updates applied.

Windows XP won't even run on 80486 based processors and below, because it not only requires CPUID, but CMPXCHG8B instructions.
With that said, I've been thinking that emulating Windows XP in PCem is completely out of the question for now.

canadianjeff wrote:

trying to get linux running on PCem this is as far as I got

also would love to see some networking support

Some Linux kernels are built using REP RET to work around an AMD bug. Don't know if that's the problem there but you'll probably run into it you try different distributions.

what does the latest change to the IDE implementation do?

Stops at least the 430VX Award BIOS from trashing the multiple transfer block size when booting. Possibly only happens with two hard drives emulated.

hmm ok, I should have looked better at what I was doing 😒

Edit: this reply was to Sarah about the changes required to run win2000.

small fix: added support for the 8Mhz model of the IBM AT.
I have failed once again at putting the ne2000 support on PCem 🙁

I have to say that PCem is really awesome! I love how I can quickly jump from an XT, 286,386 and 486. Although I must confess, I spend most of my time either on the 386 or 486. Doom runs phenomenally well under PCem, complete with glitches from the time.

I'm looking forward to when I can run OS/2 though, having to deal with emm386 and friends wasn't fun then or now...

Now if only I could beg for NE2000 support, PCem feels so lonely when you can't network... But wow what a fantastic emulator!

SA1988 wrote:

small fix: added support for the 8Mhz model of the IBM AT.
I have failed once again at putting the ne2000 support on PCem 🙁

Oh dear, can you explain to me why isn't NE2000 working properly in PCem? 🙁

ppgrainbow wrote:

SA1988 wrote:

small fix: added support for the 8Mhz model of the IBM AT.
I have failed once again at putting the ne2000 support on PCem 🙁

Oh dear, can you explain to me why isn't NE2000 working properly in PCem? 🙁

It's probably hard to do. I know Qemu (GPL & BSD) & Bochs (GPL) both have NE2000, so if I were going to just going to try to mash code, that is where I'd start. Although it doesn't mean any of it will work.

But I haven't programmed anything real in so long that I'm just sitting in the gallery I guess.

Sorry, but I was unable to respond to comments, because the router went kaput and I had to reset to make it work again.

Looking at Neozeed's comment, I believe that it would be good to add multiple configuration files. That way if you want to switch to a different PC configuration (BIOS ROM, Video BIOS ROM, hard disk and memory size), you can simply use a different config file.

So far, on my PC, I have one of the configs backed up as ami386.cfg and the default config is pcem.cfg. If I want to switch the a PC emulating a 386, I would have to make a back up of the current PCem configuration and rename ami386.cfg as pcem.cfg. And quickly jumping from a XT to a 486 and selecting a different configuration can be a bit of a hassle, but it's worth it.

What do you think? 😀