Re: PC Chips M577 / Amptron PM9900 - no POST or beeping with AT PSU, will not turn on with ATX PSU

Posted on 2021-04-22, 14:27

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Your issue sounds like PCChips "sudden silent death" syndrome, when the board just gives up and dies. It seems to be very common with their boards from the Slot 1/Super 7 era, I have 3 boards that have died in that way, and no matter how much troubleshooting or recapping, I was never able to bring …

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Re: No cache on SiS471 VLB board

Posted on 2021-04-22, 14:16

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have noticed that several SiS 471 boards have a messed up BIOS when it comes to L2 cache: in many of them the dirty tag is not set properly so WB L2 doesn't work as it should, and in others the cache timing register values set in the chipset are incorrect, resulting in low L2 speeds. This last …

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Re: Looking for the correct serial cable bracket for Floppy/IDE controller Winbond W83758P/W83757F

Posted on 2021-04-21, 15:54

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are two different pinout standards for RS-232 serial port headers in motherboards/cards (AT/EVEREX and DTK/INTEL): RS232 serial motherboard header connector pinout You can easily determine which one is supported by your card by checking whether GND connects to pin #5 or #9. Unfortunately …

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Re: Pentium OverDrive 83 on Asus 486SV2GX4 rev 2.0, problems with floppys and other storage devices

Posted on 2021-04-20, 20:17

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have tried changing writeback/writethru in the bios but not on the motherboard. Also something i will try. Is it JP21 that controls the L2 cache? The manual is not very detailed in this area. Yeah, according to this site , you need to place a jumper cap over JP21 2-3 to set L1 cache to WT. After …

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Re: Pentium OverDrive 83 on Asus 486SV2GX4 rev 2.0, problems with floppys and other storage devices

Posted on 2021-04-20, 19:01

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

First of all, try to get the latest BIOS from ASUS (it's from 1999 and should be easy to find). That may solve your problem. If that doesn't help, keep in mind that the POD83 + L1 WB cache combination can be problematic with symptoms similar to what you are experiencing. Set the jumpers for L1 WT …

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AHA-1540B/1542B patched BIOS ROM to avoid conflict with MPU-401

Posted on 2021-04-18, 19:37

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've been dabbling with SCSI quite a bit lately, and in my stash I found an Adaptec AHA-1542B card which I think suits older ISA-only machines quite well. However after installing it I encountered resource conflicts due to the fact that the default I/O port for the SCSI controller was 330h, same as …

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Re: question about AM5x86 compatability

Posted on 2021-04-17, 01:01

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's probably using the default x3 multiplier of the 5x86, so you get 100 MHz (33x3). DX4-class CPUs feature a pin called CLKMUL that can be grounded to set this multiplier to x2 (or x4 in the case of the 5x86 to give you 133MHz), but the motherboard needs to have the appropriate jumpers to do this, …

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Re: PCI Multi I/O Card, did one ever exist?

Posted on 2021-04-16, 18:58

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I wonder if that's similar to those early PCI IDE cards that came with a "paddle" connector that plugged into an ISA slot?

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Re: Can anybody identify this old 386 mainboard?

Posted on 2021-04-15, 07:19

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The "SCAT" BIOS string would indicate a VLSI design, but the support chips are all Chips & Technologies. Did they second source / rebrand VLSI designs? It's actually "SC&T" (Chips & Technologies), VLSI used the "286" string. The "S" at the beginning of the string means it's a BIOS with Setup (it …

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Re: Software besides VDIAG to test ET4000/W32 accelerator?

Posted on 2021-04-10, 18:42

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by TheMobRules

in Marvin \ Video

in Marvin \ Video

Weirdly, I can easily find documentation on the W32i and W32p on Google, but somehow plain W32 documentation is non-existent? Are there even graphics cards with a ET4000/W32 chip (not i/p) in existence? Or did they immediately skip to W32i, never producing any ET4000/W32 boards (and thus no …

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Re: ASUS P2B Rev 1.04 - Does It Need a Re-Cap?

Posted on 2021-04-10, 00:06

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hey, thanks for the reply! I should've been more clear with the statement regarding how much voltage the 3.3v rail would control: the motherboard's hardware monitor always reports a load of around 3.65 volts. This was not a problem with the PSU itself (which is now dead) as the computer it …

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Re: ASUS P2B Rev 1.04 - Does It Need a Re-Cap?

Posted on 2021-04-09, 18:23

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What do you mean when you say that the 3.3V rail is stressing the power supply by "pulling 0.35V more than it's allowed"? Is there a voltage drop or do you mean it's using more current than it should (in that case it would be amps, not volts). And how exactly would that translate to an issue with …

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Re: ASUS VL/I-486SV2G(X4) REV. 1.8 conversion and jumpers guide

Posted on 2021-04-02, 19:57

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you have a 5V supply, you can test the regulator separately by following this diagram (look up "voltage divider" if you want more details on how this works): LT1085CT.png According to the datasheet, the VREF voltage between the output and adjust terminals should be 1.25V and the IADJ current is …

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Re: Seemingly hard to find video cards like Radeon 9700, what the reason?

Posted on 2021-03-25, 04:04

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

as I understanding it the 9800XT refreshed cards didn't have the same problems. which is the one id go for I I was that interested in ATI. Correct. In fact, that also applies to newer 9800 Pro cards based on the R360 core. I have one and the shim is a bit lower than the die, which allows for proper …

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Re: Voodoo 2 - Heatsinks Needed?

Posted on 2021-03-24, 17:02

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by TheMobRules

in Marvin \ Video

in Marvin \ Video

In my experience just a decent fan (80 or 120mm) blowing air near the cards is more than enough, the chips get only slightly warm at full load even without heatsinks. On the other hand, with just heatsinks and no proper airflow they still get uncomfortably hot. So I would give priority to getting a …

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Re: Using power or turbo headers to drive 30mm fan?

Posted on 2021-03-23, 02:46

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A led is a type of diode, so if you connect it directly between Vcc and GND it will pretty much draw as much current as it is able to. And in a motherboard the PSU can output up to 20-30A on the 5V line, so it would pretty much blow instantly. As for your experience with the battery, I guess it …

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Re: psu: Lead Year ES-2150: how to turn it on? (AT&T pn)

Posted on 2021-03-22, 21:04

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have an Astec PSU with a 3-pin power-on connector, so I assume yours is similar. It's a soft-off type of design, just like ATX. In my PSU, the two outer wires (black and gray in your case) work in the same way as the green/black in ATX, so you can connect them (by using a latching switch) to turn …

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Re: MB and RAM for 486 DX-50

Posted on 2021-03-22, 20:45

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have an ASUS ISA-486 that I'd like to try with a DX-50 I got a while back, just need to replace the oscillator with a 50MHz one, and then set a jumper. Like the OP, I'd also be interested in hearing experiences of other vogoners that have DX-50 configs up and running. My board currently works fine …

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Re: Market value for popular or rare classic computer hardware

Posted on 2021-03-22, 20:30

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by TheMobRules

in Milliways

in Milliways

Well, on one side there are people out there willing to pay absurd amounts of money for random items: not long ago some dude posted on this forum and said he would pay up to $500 (!!!) for an ASUS 486 motherboard (VL/I-486SV2GX4) that is quite fast but not uncommon or particularly collectible. So …

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Re: Replacing electrolytic capacitors with polymers on my Motherboard, GPU, Soundcard. Is it a good idea?

Posted on 2021-03-22, 16:40

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by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just use replacements of the same type, no point in going with polymers unless you have specific needs (extremely low ESR on mid-00's boards for example). Even if you use electrolytics at this point they will probably outlive other hardware components, just think about how long the caps you want to …

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