Re: Detecting if a CPU is an AMD Am486 or an Intel i486 from within Windows

Posted on 2023-04-03, 17:01

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I keep hoping the BIOS will pass the information into Windows NT and the SYSTEM_INFO->wProcessorRevision; returned by GetSystemInfo() will be sensible. It's FFD0 for my Am486 DX2-66 and need to gather information for other CPUs that don't have CPUID. According to https://learn.microsoft.com/en-us/ …

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Re: Detecting if a CPU is an AMD Am486 or an Intel i486 - general advice

Posted on 2023-04-03, 16:22

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Are you sure it supports L1WB? As far as I know, "&E" means SMM and CPUID (the "SL enhanced" core), and "&EW" means L1WB support. The picture you link shows "&E". Thank you for your thoughts and I am not sure in my DX2 supports WB, CHKCPU reports it as supporting WB and it has the same CPUID as the …

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Re: Detecting if a CPU is an AMD Am486 or an Intel i486 from within Windows

Posted on 2023-04-03, 15:55

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And is there a way to get the contents of what is in the DX register after invoking RESET? "BIOS stores the CPUID value in CMOS" is not applicable in many standard PCs, although it would be nice. http://www.os2museum.com/wp/intel-486-errata/ implies that IBM PS/2 BIOSes make that value available. …

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Re: Detecting if a CPU is an AMD Am486 or an Intel i486 - general advice

Posted on 2023-04-03, 15:27

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

though it may be my DX2-66 SX807 CPUID 0436 , which also supports write-back Are you sure it supports L1WB? As far as I know, "&E" means SMM and CPUID (the "SL enhanced" core), and "&EW" means L1WB support. The picture you link shows "&E". is different to the CPUID 0435 specified in https://www.cpu …

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Re: SIMM socket only works when freshly contact cleaned

Posted on 2023-04-01, 12:54

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As the contact cleaner dries up though, it starts getting memory errors and eventually fails. I have two ideas: Possibly it's not the contact cleaner that makes it work, but you actually have a temperature dependant fault, and spraying the stuff with contact cleaner cools it down. Broken traces …

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Re: Sound Blaster AWE32 - MS-DOS and the memory expansion

Posted on 2023-03-31, 21:14

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'd guess upgrade is useless only when you're using AWEUTIL midi emulation. The game with native EMU8000 support can use larger onboard memory the very same way as Windows would do. Au contraire. Games with native EMU8000 support almost generally have SYNTHGM.SBK built into the AWE32 driver and …

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Re: Taxan EGA monitor with washed out character/colors

Posted on 2023-03-31, 17:42

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by mkarcher

in Marvin \ Video

in Marvin \ Video

Yeah, noticed that split banks thing as well. Interestingly the few strings of text in the BIOS don't seem to mention Taxan at all, only Paradise: Yes, this is obviously a Paradise BIOS, but likely adapted by Taxan. Would be funny if it turned out to be compatible with "AT&T mode" monochrome …

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Re: Sound Blaster AWE32 - MS-DOS and the memory expansion

Posted on 2023-03-31, 17:20

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, I remember reading on an older post here in VOGONS that the memory upgrade on the Sound Blaster AWE32 was only useful under MS-DOS in games that did not use protected mode - you could then load another sound bank into the upgraded memory and use it in those games. Is there any list of games …

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Re: 486 motherboard post issue - AMI code 08

Posted on 2023-03-31, 07:13

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The performance drop thing was weird - non-turbo is supposed to be about half the turbo speed and initially it was only running at that half speed, but over time began to sag to almost 1/4 the cpu's speed. The bus speeds were staying the same, but the performance just began to droop to oddly low …

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Re: 486 motherboard post issue - AMI code 08

Posted on 2023-03-30, 21:56

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm using an ATX to AT converter - there is no real "+5V POWER-GOOD" signal. That's surprising. The ATX standard also includes a POWER-GOOD signal, on pin 8 of the ATX connector. A proper adapter should connect that to pin 1 of the AT connector. I wouldn't want to reuse the 30 year old AT psu …

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Re: Taxan EGA monitor with washed out character/colors

Posted on 2023-03-30, 08:07

by

by mkarcher

in Marvin \ Video

in Marvin \ Video

Please find attached the binary file, but you might want to check if it looks alright. The dump is alright. The BIOS seems to be split into two banks of 16K each. The first bank contains the actual code, the second bank the video mode timings and fonts. Most surprising is the "BIOS size" field in …

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Re: Help identify an old PC case XT/AT ?

Posted on 2023-03-30, 07:47

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by mkarcher

in Marvin \ System Specs

in Marvin \ System Specs

That's the typical look of late 80s cases. Your case is a "deluxe" model, because you can open it without removing screws, just by pushing the buttons in the left and right side. No original IBM computer had that mechanism. Unless someone specically knows the model lineup of BMx, I don't think it's …

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Re: 486 motherboard post issue - AMI code 08

Posted on 2023-03-30, 07:30

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

PWR-Good/P8-1 didn't receive any signal (not connected) That's harmless. -5V received the +5V PWR-Good signal You must have looked at http://www.hilmanind.com/pinouts/atpwr.htm or a copy of that. The description for Pin 2 is wrong. That pin is +5V, not -5V. Connecting PWR_GOOD to +5V won't damage …

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Re: Asus PVI-486SP3 v.1.22 and 66MHz FSB

Posted on 2023-03-29, 07:37

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

dj_pirtu wrote on 2023-03-29, 06:45: ...and my mobo has OR & OT so it means no EDO? PR is later? Yes, indeed. "P" is after "O" in the alphabeht, and SiS used those code in alphabetical order.

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Re: Is this another virus

Posted on 2023-03-28, 15:43

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by mkarcher

in Milliways

in Milliways

Maybe https://xkcd.com/1180/ is a bit harsh, especially as you just had viruses, but issues like on your screen shot are common symptoms of slightly unreliable RAM or L2 cache. Try slowing down memory and cache access, try disabling caches (for testing purposes only), try running memtest86. …

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Re: 486 motherboard post issue - AMI code 08

Posted on 2023-03-28, 08:58

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a Freetech 486F30 or Genoa TURBOEXPRESS 486VL motherboard here that is stalling out on POST (no display) with code 08. AMI BIOS. Motherboard had light corrosion where the battery was, but cleaned up well and all the traces appear to be intact. I can follow AT pins 2, 3, 4, and 5 to the …

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Re: Help my floppies have Virus.Boot.NYB

Posted on 2023-03-27, 09:35

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by mkarcher

in Milliways

in Milliways

at the boot sector level (even though I read floppies don't have a MBR but a sector zero) is there a reason or two why F-Prot cant detect and clean all virus's at the same time? MBR and "boot sector" are two different concepts. MBR is the first sector of your hard drive. Floppies don't have an MBR. …

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Re: Just burned two Leopard Rev C boards .. Help?

Posted on 2023-03-27, 09:19

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And then the dumb adapter which I have now learned is the spawn of satan feeds those 5v to ground. Indeed. Those passive adapters are to be used only to connect mice/keyboards that were specifically designed to work with this kind of adapter. This is true both for passive serial-to-PS/2 and passive …

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Re: Cyrix appreciation thread

Posted on 2023-03-26, 21:41

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes sorry I dropped a C referring to Cyrix EMC87 hardware not EM87 emulator. Thanks. Now I found what you were talking about. The EMC87 is in fact a processor that fits the patent you quoted. That processor uses the Weitek pinout, enabling it to receive an instruction on address pins and an operand …

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Re: Two PCI videocards on one build

Posted on 2023-03-26, 10:07

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by mkarcher

in Marvin \ Video

in Marvin \ Video

Not between PCI slots. First slot will always take priority. Well, that's a choice of the BIOS. The BIOS enables the first VGA-compatible card it finds and ignores all other VGA-compatible cards, so they stay in the disabled state. Technically, it is perferctly possible to disable the graphics card …

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