red-ray wrote on 2025-04-29, 00:50:

I expect the stepping would be D0 rather than 0, but most DX CPUs that don't have CPUID return D0 on NT, SX return C0 and the 486DX-25 SX308 is the only CPU for which I have seen B0, see Early 80486 in https://www.geoffchappell.com/studies/windows … pu/precpuid.htm, I wonder which i486 returns A0.

It's possible it *could* still be for some buggy 1989 i486, but I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site, and it wouldn't surprise me if it was secretly some way to handle 386/486 hybrid CPUs given that the criteria for A0 involves a functioning ET bit.

nerd73 wrote on 2025-07-28, 20:49:

red-ray wrote on 2025-04-29, 00:50:

I expect the stepping would be D0 rather than 0, but most DX CPUs that don't have CPUID return D0 on NT, SX return C0 and the 486DX-25 SX308 is the only CPU for which I have seen B0, see Early 80486 in https://www.geoffchappell.com/studies/windows … pu/precpuid.htm, I wonder which i486 returns A0.

It's possible it could still be for some buggy 1989 i486, but I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site, and it wouldn't surprise me if it was secretly some way to handle 386/486 hybrid CPUs given that the criteria for A0 involves a functioning ET bit.

Many things are possible and as for "I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site" a link would be sensible.

I would like to see what the SIV Menu->Hardware->CPUID->CPU-0 panel reports for such CPUs as given they are Cyrix CPUs SIV should detect them as such as they should have DIR0.

red-ray wrote on 2025-07-29, 06:55:

nerd73 wrote on 2025-07-28, 20:49:

red-ray wrote on 2025-04-29, 00:50:

I expect the stepping would be D0 rather than 0, but most DX CPUs that don't have CPUID return D0 on NT, SX return C0 and the 486DX-25 SX308 is the only CPU for which I have seen B0, see Early 80486 in https://www.geoffchappell.com/studies/windows … pu/precpuid.htm, I wonder which i486 returns A0.

It's possible it could still be for some buggy 1989 i486, but I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site, and it wouldn't surprise me if it was secretly some way to handle 386/486 hybrid CPUs given that the criteria for A0 involves a functioning ET bit.

Many things are possible and as for "I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site" a link would be sensible.

I would like to see what the SIV Menu->Hardware->CPUID->CPU-0 panel reports for such CPUs as given they are Cyrix CPUs SIV should detect them as such as they should have DIR0.

Here you go: Re: Running Windows NT 4.0 on a Cyrix DLC/SXL/DRx2

nerd73 wrote on 2025-07-30, 16:28:

red-ray wrote on 2025-07-29, 06:55:

nerd73 wrote on 2025-07-28, 20:49:

It's possible it could still be for some buggy 1989 i486, but I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site, and it wouldn't surprise me if it was secretly some way to handle 386/486 hybrid CPUs given that the criteria for A0 involves a functioning ET bit.

Many things are possible and as for "I've seen A0 show up before on NT on Cyrix 486DLC/DRx2 CPUs on this very site" a link would be sensible.

I would like to see what the SIV Menu->Hardware->CPUID->CPU-0 panel reports for such CPUs as given they are Cyrix CPUs SIV should detect them as such as they should have DIR0.

Here you go: Re: Running Windows NT 4.0 on a Cyrix DLC/SXL/DRx2

NScaleTransitModels wrote on 2021-04-01, 02:19:

It is possible to run NT 5.0 (2000 Beta) on a 486DLC. I've successfully installed Beta 2 Build 1906 on physical hardware. Here's […]
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It is possible to run NT 5.0 (2000 Beta) on a 486DLC.
I've successfully installed Beta 2 Build 1906 on physical hardware. Here's the setup I used:
-FX-3000 motherboard
-TX486DLC/E-40GA
-Cyrix Fasmath CX-83D87-40-GP

Thank you, I can see 80486-A0 on the panel, now I just need to see what SIV reports on the Menu->Hardware->CPUID->CPU-0 panel .

I wonder what happens when no FPU is installed.

Tested on an iBook G3/500

lolo799 wrote on 2025-08-11, 19:43:

Tested on an iBook G3/500

Thank you, many things worked as I hoped, but I need to make a few small changes and once I have done this please will you try an updated SIV? I hope to have an updated test SIV some time tomorrow.

Exactly which model of PowerPC is it and what is the speed?

BTW I suspect the screen show will look better of you install the Tahoma font, it's available via Re: SIV support for 386/486/586 class CPUs and 3Dfx + Matrox GPUs

red-ray wrote on 2025-08-11, 20:25:

Thank you, many things worked as I hoped, but I need to make a few small changes and once I have done this please will you try an updated SIV? I hope to have an updated test SIV some time tomorrow.

Exactly which model of PowerPC is it and what is the speed?

BTW I suspect the screen show will look better of you install the Tahoma font, it's available via Re: SIV support for 386/486/586 class CPUs and 3Dfx + Matrox GPUs

It's this one:
https://everymac.com/systems/apple/ibook/spec … /ibook_500.html

I'll keep NT4 on it for the time being, happy to do more tests.
I'll try the font but I can't take screenshots, only pictures of the screen (which starts suffering from vinegar syndrome).

lolo799 wrote on 2025-08-11, 20:57:

I can't take screenshots, only pictures of the screen

Oh!, is there no PrtSc key? For the SIV screens you can press [Copy] then paste the image into MS Paint.

On the [ Windows ] screen SIV reported "Hardware Abstraction Error No more data is available." which I have never seen before. On my PowerStack SIV reports HAL PowerPC HAL. There should be a sub-key below HKEY_LOCAL_MACHINE\HARDWARE\RESOURCEMAP\Hardware Abstraction Layer, is there? It would also be handy to see HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0.

What do the Windows NT Diagnostics report as the HAL?

lolo799 wrote on 2025-08-11, 20:57:

I'll keep NT4 on it for the time being, happy to do more tests.

Thank you for the link, I also found https://en.wikipedia.org/wiki/List_of_Mac_mod … PU_type#PowerPC which is handy. What I really need to know is what all the Family + Model numbers are, I plan to look for them tomorrow. I just found a list of PVR values.

I have just uploaded the SIV32P V5.83 Book-05 test SIV which should do rather better, please may I have new save files?

BTW for you you get files to/from the iBook? My PowerStack is networked, but I don't think your system is.

Your PowerStack is officially supported but NT4 is only working on Apple machines due to the work of https://github.com/Wack0/maciNTosh
USB isn't supported so no external keyboard, and neither is the ethernet chip.

MacOS doesn't use the printscreen key but some shortcut I can't remember at the moment, the Ibook keyboard is pretty sparse.

I use firewire target mode to get files from the iBook, and sometimes a cd-rw to copy files to it to avoid rebooting all the time.

lolo799 wrote on 2025-08-12, 16:48:

Your PowerStack is officially supported but NT4 is only working on Apple machines due to the work of https://github.com/Wack0/maciNTosh

Thank you for the new save files and I am well aware you are using maciNTosh. Have you ever reported any bugs? I suspect I will have to as some things don't seem to be working in particular HalTranslateBusAddress(). I have added Menu->System->ACPI + PnP->HAL Translations which should show the issue with HalTranslateBusAddress(), on my system I get as below.

I suspect it will report translation errors on your system, also notice that SIV now reports my GPU memory clock as I found and fixed an I/O Port access bug.

In general SIV did much better on your system and I have now fixed I/O Port access so please may I have new save files generated with SIV32P V5.83 Worm-05? They should contain [translation] so I don't need a screen shot.

After pondering PrtSc I wonder, do you feel should I add Menu->Edit->Copy Screen and/or rename Menu->Edit->Copy Bitmap to Menu->Edit->Copy Window?

red-ray wrote on 2025-08-12, 18:03:

After pondering PrtSc I wonder, do you feel should I add Menu->Edit->Copy Screen and/or rename Menu->Edit->Copy Bitmap to Menu->Edit->Copy Window?

Renaming the Copy button would be enough I think.

lolo799 wrote on 2025-08-12, 20:06:

Renaming the Copy button would be enough I think.

Thank you, it's as I suspected it would be, HalTranslateBusAddress() is failing when I suspect it should not. Below you should see it's failing on your system, but is fine on my PowerStack.

I have posted https://github.com/Wack0/maciNTosh/issues/63, fingers crossed for a fixed HAL.

While I wait I for a new HAL I will fix the L2 Cache information and look into on how to do the PowerPC version of RDTSC so SIV can report the correct CPU speed.

lolo799 wrote on 2025-08-12, 20:06:

Renaming the Copy button would be enough I think.

OK I have made the change in SIV V5.83 Beta-05. I have also finally found PAS.exe, the Motorola PowerPC assembler for Windows NT and added PowerPC TB (TSC) reading support so please may I have a screen shot of Menu->Hardware->CPU Detail->CPU Timers + new save files ?

SIV32P V5.83 Tick-05 should also report the correct L2 cache information, is it correct?

The reason that HalTranslateBusAddress() fails on Apple is that there is no ISA bus.

red-ray wrote on 2025-08-13, 17:20:

The reason that HalTranslateBusAddress() fails on Apple is that there is no ISA bus.

I was going to comment on the lack of ISA, yeah.
I'll test the new version when I can, in a week or 10 days from now.

lolo799 wrote on 2025-08-13, 18:08:

I'll test the new version when I can, in a week or 10 days from now.

OK, SIV V5.83 Beta-05 is now released so please use that.

BTW It also has Menu->Edit->Copy Desktop, if you do SIV32P -AIOCTL you can also use Menu->File->Profile->Hotkeys to setup a hotkey.