Dietmar

@ProgramHacker This will not work Dietmar

@roytam1 I want to do this, but for those a lot of cmpxchg8b there, it is just not enough free place in it at the end of their .text section. And I have small success with to enlarge the .text section. Can you enlarge the .text section of my german files? And write me, where those free place is now in those files. Then I will do the modd Dietmar

@roytam1 This problem I have had before. Now I always look, if still the modified ntoskrnl.exe is at its place. I think, that the same happens to you. In the very last reboot, some files are changed back to their original one. Because I do not change them in sp3.cab or dll or driver folder. For to overcome this, I just put out HD before last reboot and copy by hand back all the modded files. This works for me. Until now I do not succeed to install any PCI to Sata or IDE controller under XP. With the original PIO 3 IDE controller on the Shuttle Hot 433 board, the transfer speed is about 7MByte/s, brrr.. I tried really all. No driver is even correct installed under running XP. I tried: Promise TX2 300, Silicon 3114, Silicon 3112 and a no name from China. "Best" result shows the Promise driver, but even when XP tells, that its driver is correct installed, I never see a harddisk via this adapter, nor I can boot from it Dietmar

@roytam1 Do you have success with installing your modded english XP SP3 on a 486 cpu? Which version do you use? Do you change anything compared with my files? I am soso curious, can you send me your modded files? Just now I am installing my german xp486.iso direct onto an AMD 133MHZ 486 cpu Dietmar

Hi, is there a tool or an adapter, where you can put your xp.iso on it, so that it looks like a real CD-Rom? Connector to compi can be IDE or Sata or PCI. No USB connector, because old motherboards know nothing about USB. I ask this, because I notice, that some of my burned CD-Roms do not work any longer, because of age(?) Dietmar

@roytam1 I think, that you miss a 90 at the end of this Dietmar Comparing files WINNT32U.DLL and ..\ENG-HACK\WINNT32U.DLL 000323CC: 75 EB 0003739E: 0F 90 0003739F: 84 90 000373A0: 43 90 000373A1: 07 90 000373A2: 00 90 000373A3: 00 90 000373AE: 0F 90 000373AF: 84 90 000373B0: 33 90 000373B1: 07 90 000373B2: 00 90 <==

@roytam1 Have you tested with the modded WINNT32A.DLL and WINNT32U.DLL, if the hack in ntoskrnl.exe against Bug Check 0x5D UNSUPPORTED_PROCESSOR is not necessary any longer Dietmar

@roytam1 With my XP TXTSETUP runs ok. But then, after first reboot, compi hangs after about 4 min. Sometimes hanging after about 4 min and sometimes during detect of devices (37min to wait is shown). Are WINNT32A.DLL and WINNT32U.DLL on the german CD the same as on English ones? Please tell me the crack or send me the already modded files Dietmar

Yessssaaa, it installs XP SP3 on my AMD 486 133MHZ cpu !!!!!!!!!!!!!!!!!!!!!!!!! Even I do not get any Bsod before, I did exact the same extras as you: Extra setupldr.bin patch 75 to EB in 0x23513 (strange, because it has CPUID), and replacing NTKRNLMP.EXE with our hacked NTOSKRNL.EXE, niccccccccccccccccccccceee.. And I also delete logagent.exe and wmnetmgr.dll from the XP SP3 install CD, because those 2 are the only files left, with CMPXCHG8b opcode in it Dietmar Here is the full fun https://ufile.io/kresk3y1

@roytam1 I am just testing on Shuttle Hot 433 board with AMD 133 MHZ486 cpu AMD AM5x86-P75 Dietmar EDIT: On real 486 compi, the same reboot happens before the F8 appears. Is there something other, that you change on my "Source" CD for setup of german XP SP3 with all those modded files?

@roytam1 I replace the second ntdll.dll with my modded one but get the same reboot just at the end of the Setup process, before you have to hit F8. Please, can you tell me, what simulator you use for the AMD 486 cpu. And is there a possibility, even in this very first Setup of XP to let Windbg watch it, may be via a crash debug log Dietmar

@roytam1 With this changes, can you install XP SP3 now on a 486 cpu Dietmar

@roytam1 The ntdll.dll is patched. So I dont know, where this Bsod happens Dietmar EDIT: Ah, I see, there is a second ntdll.dll on the xp.iso, crazy;))..

@roytam1 Please describe more exact this Bsod. I test all my modded files a lot and now no kind of such a Bsod happens to me. Does it happen during Setup of XP, my modded setupldr.exe and setupldr.bin together with my modded ntdll.dll Dietmar

@roytam1 Until now,all the 486 cpu's are treated as the Pentium Overdrive 486 Podp5v83.This makes the aktual Xp slow on the Amd processors.For to speed them up a lot,we need to build a real xp486.iso ,where the correct cpu is listened via Cpuid.For me this is hard work,because no Windbg during very first steps of Setup.May be,in this situation an emulation can help a lot,when this emulation can build a real amd486 cpu Dietmar Edit: A elegant solution for this would be,to use the Source for Xp Sp1, adding all 486 cpu's there and just compile a new setupldr.exe and *.bin

Full working XP SP3 for any 486 cpu, good luck Dietmar https://ufile.io/j52nyg24

After a new, full install of XP SP3 on a 486 cpu, I get a boottime from less than 2 min. Now XP uses full 256MB ram, cached with 1024 Cache memory. The load of the cpu goes down to 35%, when doing nothing. With this XP you can work, oh..soso much fun Dietmar

@genieautravail ChatGPT is blind as much as possible in coding. Nearly nothing is correct, even most easy errors. BUT: You can use ChatGPT for to get new ideas. The hard way to make them come true, is ALWAYS on you Dietmar

Here is the source for the 486 fun above Dietmar https://ufile.io/i3j8idk7

Here is the working XP SP3 for 486 cpu. It also contains in an extra folder all the for 486 modded files. It is after install in TXT-Setup before first reboot. I tested it on an Amd 133 -p75 cpu. As CD I use my german VL xp.iso with XP SP3 Dietmar https://ufile.io/upxbmmse

@Cixert It is not difficult, to change from Standard PC to Acpi Multiprocessor via a Bios, that supports ACPI for XP. Your case is very different from this: After Bios update, your DSDT and SSDT tables have changed. Now, XP CANT boot any longer with acpi via them. From my experiments, mostly this goes to an "new" incompatible Graphik Mode. Your problem can be easy solved with the acpi patcher at boot time from @Mov AX, 0xDEAD. There you give them via modded ntldr always your old acpi tables, that you have fetched for example via RWEverthing in binary form. After this, your compi works like before, tricking out the new Bios Dietmar PS: Another way is just to go back to your old Bios. But this can be impossible, even with EEprom Bios chip writer.

@Cixert Yes, I try also the 486-step3 hal.dll. Same reboot until now. @ProgramHacker With 256 MB cached ram and 160 MHZ, you can work with XP SP3 on a 486 cpu. It is still slow but enough for easy tasks. For me it is just fun as much as possible, to understand XP much better and how to speed it up Dietmar

I think, that the reboot of the 486 compi during Setup happens, because CPUID gives values in all those registers, which tell Setup, that it is an unsupported cpu. The same happened when using a ready IDE install and can be overcome only with the nice hack from @roytam1 against Bsod 0x0000005D, Bug Check UNSUPPORTED_PROCESSOR. May be a working solution would be, to fake the 486 cpu with the CPUID settings of the Intel Overdrive 486 cpu podp5v83. But this needs to be checked careful. Anyway I get stable XP SP3 on 2 different Amd 486 cpu's, 100 MHZ and 133 MHZ. With updating the Cache to 1024 KB, may be, that XP uses all the memory and then it will be much faster Dietmar

It workkkkkkkkkkkkkkkkkkkkkkkkkkkkssssssssssssssssssssssss Just now I am installing XP SP3 via CD on an AMD 486 100MHZ cpu Dietmar EDIT: But 486 compi reboots at the place, Windows is starting, when the harddisk should be seen.. EDIT2: Rom also was not build in one day. So, for today it is a nice result to overcome the CMPXCHG8B check in XP. Here are all my files until now for 486 XP SP3 boot and install https://ufile.io/7bgj5rv1