Hacking/Replacing Phoenix Bios 4.04 on 486 board

Posted on 2022-08-30, 17:06

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! I recently got a good deal on a 486 board from a Compaq 7100 series Desktop PC. It is based on the UMC8881/8886 chipset and comes with decent sound and crappy VGA on board. It is this model: https://theretroweb.com/motherboards/s/trigem-pl4600c The board came with an AMD X5-133 installed. I had …

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Re: set MAC address on 4CoreDual-VSTA

Posted on 2021-12-23, 11:32

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Worked perfectly, thanks a lot!! Finally no more error message at boot. Even with the integrated NIC disabled it would pop up and needed F1 confirmation. And there wasn't any "halt on errors" option that I could find either. The board came in a pile of scrap, had the expected couple dozens of bent …

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set MAC address on 4CoreDual-VSTA

Posted on 2021-12-23, 00:26

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! I managed to revive a scrapped and severly damaged ASRock 4CoreDual-VSTA and it works great. However I'm getting the dreaded "MAC adress invalid in both CMOS and flash" Bios message. There used to be a MAC tool that people used on this exact board to set the MAC address and fix this error. …

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Re: P3B-F and Coppermine in slotket troubles

Posted on 2021-08-06, 12:29

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

@kaputnik, you made my day. Even though I have blisters on my fingers now. Using your technique and making a mess with WD40 eventually brought all my 370 CPUs to life on the P3B-F. Even the Cyrix III 600, which never worked in any of my boards and thus I thought was dead, runs fine not only in that …

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Re: P3B-F and Coppermine in slotket troubles

Posted on 2021-08-06, 11:01

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

@kaputnik LOL it worked, at least to some degree. I took out the slotket and CPUs dozens of times already and did not seriously believe in any remaining contact problems anymore. This time, I flushed the whole socket with WD40 and closed/opened it a couple dozen times with a CPU inserted. And voila: …

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P3B-F and Coppermine in slotket troubles

Posted on 2021-08-06, 09:14

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! Can anyone confirm that this slotket model works with a coppermine P3, preferably in a P3B-F 1.03? Because I can't get it to work. With a 800EB SL464 or a 900MHz Celeron SL5EX it never outputs a single code to the POST card. With a 566MHz SL5L5 Celeron it will output the first POST code C0 most …

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Re: CRT “crack” sound + picture flicker

Posted on 2021-06-01, 07:46

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I’ve got 9 Compaq CRT screens from a job lot in my shed at the moment and I have to get rid of some as I don’t have the space! A few of them when first turned on made a little “crack” sound from inside the screen along with the picture flickering as it made the sound The frequency of this varies …

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Re: 486 post-repair PS/2 Keyboard protocol issue

Posted on 2020-10-07, 10:19

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That sounds like a reasonable explanation. It had to be BIOS code being executed by an interrupt every~400ms, as these accesses began right before booting DOS but not before POST had finished. The AMI "Turbo Switch Function" is not as self explanatory it seems. In the book "The BIOS Companion", I …

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Re: 486 post-repair PS/2 Keyboard protocol issue

Posted on 2020-10-03, 10:38

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Now thats unexpected: The freeze was triggered by the bios "Turbo switch function". If that function is turned on, which is default, there is a ~200us burst of activity on the CPU M/IO# line every ~400ms. During that time, the 82C495SLC LMCS#/KBCS# line goes nuts. Those two lines are or'ed together …

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486 post-repair PS/2 Keyboard protocol issue

Posted on 2020-10-01, 19:56

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! I recently acquired a 486 VLB board with some massive battery corrosion damage. Dozens of pins and pads of the QFP 82C206 AT bus controller had detached. After some 30+ patch wires I got this baby back to life. Looks like a big mess of wires, but it runs runs a DX2-66@80 together with VLB IDE …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-24, 07:27

by

by watz

in Marvin \ Video

in Marvin \ Video

I just fixed an old Socket A board by recapping it. Its got a Sempron 2300+ @1567Mhz. installed. Just for fun, I plugged in the Voodoo 1 and booted the same SD card into Win98 DOS mode, not expecting much to work due to the CPU speed. Tombraider demo works fine as usual. Descent 2 executables lock …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-22, 13:02

by

by watz

in Marvin \ Video

in Marvin \ Video

It may be that some capacitor(s) on the voltage line are busted and one board has much better power regulation while the other does not? Yes thats what I was thinking, too, and thats why I've put some extra caps on the Voodoo and changed the PSU. The card itself has only tantalum and ceramic caps …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-22, 07:38

by

by watz

in Marvin \ Video

in Marvin \ Video

I've tried the ISA card in the VX board and the crash is still there. So I can also rule out the other two PCI main video cards as cause. Manually reassigning PCI memory resources of the Voodoo didn't do anything either. Finally, I switched back to the P3 board again and the Voodoo is working …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-21, 22:00

by

by watz

in Marvin \ Video

in Marvin \ Video

Try a different main video card if You have one. If it works perfectly on the P3 system then it won't be the voodoo1 that is the problem. Maybe it's not properly switching between video cards. Software/driver issues? Thats the thing: I've used the exact same SD card to boot all three boards. …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-21, 11:55

by

by watz

in Marvin \ Video

in Marvin \ Video

I'm going to try a different mainboard now. I'm going crazy. The card works fine in a P3B board (tried Quake2, Unreal, 3D Mark 99). It does not work in another VX based board I got. That gives the following results: Asus P55T2P4 (430HX), K6-2 @400 / Pentium @133, 32 MB EDO, MGA450 PCI: - DOS Tomb …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-21, 11:02

by

by watz

in Marvin \ Video

in Marvin \ Video

Weird. Good job finding that. Not everything is quite right yet, though. The Tombraider demo works abolutely flawlessly every time. However everything I've tried in Win98 as well as 3dfx Descent 2 in DOS still gives me the yellow screen. I've swapped the K6-2 400 for a P133 without any effect. I'm …

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Re: 3dfx Voodoo 1 yellow screen

Posted on 2020-06-21, 00:10

by

by watz

in Marvin \ Video

in Marvin \ Video

FIXED!! LOL The TMU RAS line wasn't connected to its RAM chips anymore. The zero Ohm resistor R202 in the RAS line was entirely open. It seems to serve abolutely no purpose as its not even jumping across any traces. Maybe someone intended to put a series resistor there, but why isn't there such a …

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3dfx Voodoo 1 yellow screen

Posted on 2020-06-20, 21:45

by

by watz

in Marvin \ Video

in Marvin \ Video

Hi! I've acquired an old Gainward GW703 4MB Vodoo 1 for cheap. It seems to be broken however: As soon as I switch any game to glide mode, the card switches to the correct resolution but displays only a large rectangle filled with a yellow color gradient that occupies almost the entire screen. Thats …

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Re: ASUS P55T2P4 giving RAM errors

Posted on 2020-04-29, 17:06

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK this is getting embarassing now... Turned out this BAT board was missing a screw hole where the old BAT board had one. So when mounting the board, I've shorted out some pins of the RAM sockets with a screw post under the board. So it was a kind of hardware fault after all ;-) Board still works. …

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ASUS P55T2P4 giving RAM errors

Posted on 2020-04-29, 14:15

by

by watz

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! I recently aquired a BAT format P55T2P4 rev 2.3 board. I've inserted known good P133 and known good PS2 RAM modules (they work in another 430VX based board just fine). The board is jumpered correctly for this CPU and the onboard cache. Yet it gives me the dreaded long beep error code indicating …

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