Re: (486) Floppy port doesn't work when Yamaha soundcard installed

Posted on 2022-06-01, 18:51

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Okay, well I just found that the secondary IDE port also doesn't work when the soundcard is installed. Not sure why I didn't put 1 and 1 together as this being the cause of being unable to detect hard drives on IDE2. I guess I didn't notice that my cd-rom drive also stopped working after installing …

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Re: (486) Floppy port doesn't work when Yamaha soundcard installed

Posted on 2022-06-01, 18:05

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Unrelated, but finally received a replacement fan after some delays. It's nice to have this system quiet now, instead of the re-oiled, still-grinding, sometimes stalling Sunon fan that this replaced.

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Re: (486) Floppy port doesn't work when Yamaha soundcard installed

Posted on 2022-05-31, 23:56

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Horun wrote on 2022-05-31, 23:43: Can you post a picture of the back of your ATC-6631 ? I want to see if IRQ6 and/or DMA2 have slot connections... Sure thing - attached

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Re: (486) Floppy port doesn't work when Yamaha soundcard installed

Posted on 2022-05-31, 16:59

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The floppy controller would use IRQ 6, DMA 2, and i/o ports 3f2, 3f4, and 3f5 and this would not be configurable. Floppy drives being universal, I don't see that the Yamaha card would even allow itself to overlap with those resources, and even if it did, I would expect such initialization to have …

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(486) Floppy port doesn't work when Yamaha soundcard installed

Posted on 2022-05-31, 04:44

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So I'm trying to get an old 486 going that I purchased "complete" some time back. After some headaches, I found that this FIC 486-PVT-IO board is very picky about what IDE CDROM drives will work with a windows 98 boot floppy. Surprisingly, it also has the 504MB limit in the BIOS, dated from 1995. …

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Re: SS7 MVP3 Motherboard - stalls on POST with code 61

Posted on 2022-04-08, 16:10

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Chip pins looks fine so it might be faulty after all. BTW you said the mobo works with L2 disabled, but what about timings? Did you try the slowest cache settings possible, still no-go? My only options are "fast" and "fastest", or something like that, and nothing else. It defaults to the slower …

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Re: SS7 MVP3 Motherboard - stalls on POST with code 61

Posted on 2022-04-07, 22:35

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's too bad, but if there's only one cache chip that means that it only has 512k L2? The performance hit to a K6-3+ would be pretty small in that case. I agree with your conclusion that it's likely the cache chip itself that's faulty, which could be replaced with the right tools; but now that …

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Re: SS7 MVP3 Motherboard - stalls on POST with code 61

Posted on 2022-04-07, 21:51

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Inspect the cache chips, sometimes when mishandled the pins get bent and short, or lift from pads. Sometimes even damp dirt between pins can cause issues so if the mobo is dirty just give it a good bath in clean water (plus maybe some dish washing detergent) with a soft brush. Let it dry for at …

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SS7 MVP3 Motherboard - stalls on POST with code 61

Posted on 2022-04-07, 16:10

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

New board here that I'm troubleshooting - S7-MVP3 https://www.elhvb.com/mobokive/Archive/Yan-Jen/s7-mvp3/s7-mvp3.pdf This board stalls during POST with code 61: Award (61)Try to turn on level 2 cache. Set the boot up speed according to setup setting. Last chance for chipset initialization. Last …

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Re: AT Keyboard connector inductor bad?

Posted on 2022-03-09, 06:07

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Sounds great so maybe you could check that resistor to see if it uses wire and has some inductance (basically some low R value resistors use wire wrap internally and not carbon) which you could then use as L1 instead of trying to order a SMT inductor. Just a thought :) added: check Mouser, they …

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Re: AT Keyboard connector inductor bad?

Posted on 2022-03-09, 03:35

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

jmarsh wrote on 2022-03-09, 03:33: Would suggest making sure the resistance of the fuse is close to zero. Yes, 0.1ohms after zero'd to the probe wire's normal resistance. Jumpering over the fuse with multimeter probes shows no change in behavior. Do the same on the inductor, keyboard lights up.

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Re: AT Keyboard connector inductor bad?

Posted on 2022-03-09, 03:31

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I would put the jumper in disabled (2-3) and temp short across L1 and see if the KB works. It should be somewhere from 1uH to 4uH and is for noise reduction if same as most later AT/early ATX boards. You might get away with out it.... fwiw: The manual at Asus does not show that jumper for P5A-B but …

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AT Keyboard connector inductor bad?

Posted on 2022-03-09, 02:56

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have an Asus P5A -B here with a bad keyboard connector. I found that wiggling it would make the keyboard come and go - cleaned the contacts and re-soldered the connections to the board, but same thing. Further narrowed it down to this inductor - very light pressure on this component, the keyboard …

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Resolution scaling of IBM 4945-20X T120 20in 1600x1200 monitor

Posted on 2021-12-26, 20:30

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Does anyone know if the IBM T120 does integer scaling of 320x240 content? There's next to no data online about this display. Looking at grabbing one if it's similar to the Dell 2007 displays in this aspect. Manual: https://www.ibm.com/support/pages/installatio … bm-t120-monitor

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Re: Cachechk stalls on 80486 Cyrix CPUs

Posted on 2021-12-14, 20:03

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

But Doom was playable for me on a fast ISA card back in the day. Hah! Back then, 5fps was "playable" for many games to me, and 10-15 on later riva 128 cards in some hardware accelerated games was amazing/"buttery smooth". I may still have a computer magazine in a box that showed how fast a 15fps …

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Re: Cachechk stalls on 80486 Cyrix CPUs

Posted on 2021-12-13, 19:11

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As an update, I found some odd behavior with the board and (default) BIOS sleep timer. The 15-second setting appears to correlate with cachechk reaching the 3rd Megabyte of RAM. Perhaps Cyrix chips don't handle the implemented sleep timer. Disabling this BIOS setting did get rid of "it looks like …

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Re: Cachechk stalls on 80486 Cyrix CPUs

Posted on 2021-12-13, 06:54

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The motherboard is running with 4x16GB 30-pin SIMMS and 256KB of L2 cache. 4 x 16GB on a 486? I guess you mean 4 x 16MB :) Can't help with your question though, sorry. Errrr, yeah. I only have four matching 30-pin sticks of 16MB, so testing with a crazy 64MB of RAM on a 486. More appropriate would …

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Cachechk stalls on 80486 Cyrix CPUs

Posted on 2021-12-13, 06:14

by

by Masejoer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a MV035 motherboard here (actually two, both behave the same) and can run cachechk (v4 2/7/96) on Intel and AMD CPUs (33-100MHz), but my Cyrix 486 DX4-100 and 5x86-100GP CPUs both stall out in cachechk when on line/Megabyte "3." Only a reboot gets the system responding again. I didn't find …

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Re: Voodoo 2 - Memory error with TMU enabled

Posted on 2021-10-25, 01:28

by

by Masejoer

in Marvin \ Video

in Marvin \ Video

Well, I seemed to find a half dozen slightly wiggly joints on the "top" and right sides of chip 0009 and went to touch the spots up, and now have two overlapping pins from one pin that slid over and bridged simply from some tension that I released as I flowed each joint. Not sure where my blade tip …

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Re: Voodoo 2 - Memory error with TMU enabled

Posted on 2021-10-24, 23:31

by

by Masejoer

in Marvin \ Video

in Marvin \ Video

sdz wrote on 2021-10-24, 23:23: Poke the TMU pins, even if they look good under the microscope. Yeah, I was just doing that a bit more with a better tool - giving each pin a small tug to check for weak solder joints. Are chips 0010 the TMUs? Still googling to try to find verification on which chip …

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