Re: Help save my 386 motherboard.

Posted on 2020-07-14, 16:59

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Those would be ceramic capacitors. The marking on them are in pico farads, so e.g. 103 means 10x10^3 pico => 10 nano farads. If it is just 10 means 10 pico farads. You don't need to replace these as they rarely fail.

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Re: Help with XT boarf

Posted on 2020-07-14, 04:56

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Very nice little board, albeit a little dirty. Your VGA card is 8-bit or set to 8-bit already I guess? There is a DIP switch on your XT (SW-A, the red one), try setting the monitor selection to other settings (SW-A/5&6, on-on, off-on, on-off) instead of monochrome (off-off). Your board looks like …

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Re: failed BIOS update and programming an AT49F002NT DIP-32 EEPROM BIOS

Posted on 2020-07-12, 03:40

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

TL866 is a very good programmer, I have one myself. But if you don't use it regularly, you could opt for the other alternatives others mentioned though, i.e. buy a preprogrammed BIOS chip or ask a fellow forumer to program it for you. It'll be much cheaper.

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Re: AT PSU Choices for 486, advice on the better gamble

Posted on 2020-07-12, 03:18

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Btw, I would suggest removing the switch on your case and attach the one that came with the PSU, if they are the same size. If you cut those shrink tube, for safety you'll need to some how wrap it back afterwards, and I seriously hate using those electrical tape, which is sticky and messy and would …

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Re: failed BIOS update and programming an AT49F002NT DIP-32 EEPROM BIOS

Posted on 2020-07-12, 02:56

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

SD won't work as it needs IDE hdd routines which is in the main section of the BIOS which is now corrupted. A floppy drive is needed. Just reset the CMOS by jumper and try again. This won't work if the boot block is also corrupted though, e.g. you used the /wb command to force awdflash to program …

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Re: AT PSU Choices for 486, advice on the better gamble

Posted on 2020-07-12, 02:49

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Mattyice1994 wrote on 2020-07-11, 23:21: Also, it doesn't say it is a "switching power supply" anywhere.. any idea if it is? It is a switching power supply, it has a switch... 😜 Ok seriously, it is a switching power supply. You won't find any of those old school linear power supply with huge …

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Re: failed BIOS update and programming an AT49F002NT DIP-32 EEPROM BIOS

Posted on 2020-07-12, 01:37

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Atmel AT49F002 flash ROM has boot block, which usually the Award flash utility won't touch unless forced to. You could try hooking up a floppy drive and see if its LED lights up when power on, if so you could set up a floppy disk to auto reprogram the flash. For example, you could put these in …

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Re: Soyo 019R1 - Late 386 board revival attempt

Posted on 2020-07-11, 13:39

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you have a multimeter you can do a quick check on the power rails to ground to see if there are any shorts.

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-11, 13:08

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

... And K10 architecture has minimum able mul x0.5, i.e. it will be CPU 100 MHz at FSB 200MHz (HyperTransport 800MHz). I have tried this and it really works! If you are programming FID=0 DID=4 to MSR it functions as a 0.5x multiplier i.e. 100MHz. Tested with AIDA16 K10 at 100MHz is not a very fast …

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-11, 12:56

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

CPUSPD version 1.5 released: Added support for ODCM (On Demand Clock Modulation), for Intel Pentium 4 and newer CPUs (Pentium D, Dual Core, Core, Core2). This is very exciting news for owners of Pentium 4, Pentium D, Dual Core, Core, and Core 2. For these CPU, now we have 4 types of hardware …

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-11, 12:10

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok 2 items added to the to do list: investigate throttle sigfault for Core i and K10 south bridges. That'll keep me busy for a while. 😀 I do have an AM3 board with SB710, so further testing is not difficult.

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Re: Diagnosing and fixing old AMD386DX 40 MHz boads

Posted on 2020-07-11, 10:31

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not sure about 486s, but usually CPU's reset line is generated by the chipset. For example, here is one for the Pentium 4. The reset button/circuitry sends a signal to the south bridge, south bridge relays the reset to the I/O slots and north bridge, and the north bridge sends a reset to CPU. Since …

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-11, 09:51

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

@zyzzle Thank you very much for your encouragement. I've never tested the program at all on any Core i system, as my original plan was to support up to Core 2 only. I'm quite surprised that south bridge throttling didn't work though, as it is based on ACPI. I did have a chance before to look at …

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Re: Soyo 019R1 - Late 386 board revival attempt

Posted on 2020-07-11, 09:30

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So is it working now? :) I actually suspect more on the tantalum caps than the corrosion, even though the corrosion is real bad. Usually when there is a short, the PSU should shut down instead of tripping the circuit breaker. In your case that didn't happen, so perhaps the quality of the PSU is …

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Re: Diagnosing and fixing old AMD386DX 40 MHz boads

Posted on 2020-07-11, 07:34

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is a 386 BIOS image collection thread if you like to upload your BIOS image. As for the traces, my suggestion is to check all traces near the corroded area. But if you would like to start with the reset line, you can start tracing it from the ISA slot, pin B2. Please see ISA pinout here . …

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Re: DFI Lanparty NF4 issues

Posted on 2020-07-10, 07:21

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's unlikely to be bios problem since you don't even have the fan spinning. There is no power supplied to the board, which would be the case if there is a short and the PSU protection circuit kicks in and shut itself down. Either that or the PSU is overloaded.

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Re: Diagnosing and fixing old AMD386DX 40 MHz boads

Posted on 2020-07-10, 05:32

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by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If the POST card reset LED stays on then it's the reset circuitry issue. I would recheck the battery damaged area for broken traces.

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Re: DFI Lanparty NF4 issues

Posted on 2020-07-10, 05:25

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks like a short somewhere on the motherboard preventing the PSU from starting. If you have a multimeter, could measure all the voltage rails against ground to look for short, especially the 12V 4pin CPU connector.

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-10, 04:50

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

According to the docs, ODCM was originally intended for thermal throttling of the CPU, so that the CPU could throttle down when overheating is detected. I checked the msr tables for PD, Core, and Core2, the ODCM msr does exist in them so I'm not sure why Intel put that statement (It's on page 14-30, …

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Re: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win98 Retro Gaming

Posted on 2020-07-09, 11:26

by

by kalohimal

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

@PARUS I'll start working on it. It's quite simple to include so maybe just a few days of programming and testing time will do. Edit: ok it is not so simple. For CPUs with single core and no multithread then it's straight forward. For CPU with multithread, all logical processors must be set, …

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