Re: Debug an 8086 that won't power up

Posted on 2022-09-21, 07:15

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Measured the OUT1 pin (pin 13) on the 8253 and I don't see any activity (it goes high as soon as I power on the computer but never changes) I also measured the CS pin (pin 6) on the 8255 and it appears to be a regular interval but I don't know what kind of signal I should be expecting.

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Re: Debug an 8086 that won't power up

Posted on 2022-09-21, 00:41

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Also there seems to be activity on the data bus too. I measured activity on AD0 through A14 and the data bus pins on all of the DRAM chips.

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Re: Debug an 8086 that won't power up

Posted on 2022-09-21, 00:19

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well it looks like it's time to break out the oscilloscope :) ok so far the clock signal looks good. Also the PC tester is reporting a brief reset light and a steady ready light. I'm trying to follow along with an Adrian's Digital Basement video about what else to measure. Anyone have a …

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Re: Debug an 8086 that won't power up

Posted on 2022-09-18, 20:38

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by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was able to isolate and replace a single shorted tantalum capacitor and now the power supply starts up! I measured all the voltage rails and they are solidly on spec. Now I'm trying to get a beep or a video signal and so far I haven't been able to get anything. Things I have tried so far: 1: tried …

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Re: Debug an 8086 that won't power up

Posted on 2022-09-17, 02:35

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In continuity mode I'm getting a short beep between ground and +5 and a solid beep between ground and +12. Nothing on -5 or -12. Days also found a suspicious tantalum that appears darker than the rest. As for trying it without the card, so far I've tried it with a CGA card only and with no cards at …

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Debug an 8086 that won't power up

Posted on 2022-09-16, 22:42

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I recently got an old 8086 computer that I'm trying to bring back to life. It had a floppy controller card with a leaky battery that unfortunately spilled onto the motherboard. Before powering it on I removed all the sockets that had any appearance of corrosion, tested all of the DRAM in a Retro …

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Re: Getting OpenGL Stereo working

Posted on 2022-07-25, 04:50

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by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

GLQuake seems to have a bug, in 1.09 (GLQuake 0.95) if i set the X separation to a non-zero value which is supposed to enable stereo mode the screen becomes a garbled mess. Quake 2 however does work, it just takes a couple steps. First you need to run the following commands (from http://benryves.com …

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Re: Getting OpenGL Stereo working

Posted on 2022-07-23, 20:18

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by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Success! The final configuration I needed was to use the official Diamond FireGL 1000 Pro NT drivers (specifically nt41kp6f.exe, I`ll upload it to the Vogons Driver Database) and to set my graphics mode to 640x480 16bpp with a 120Hz refresh rate, though I think it would work as low as 60Hz. My …

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Getting OpenGL Stereo working

Posted on 2022-07-22, 21:24

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by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Anyone have any experience or know of any documentation related to OpenGL Stereo Graphics? I have been trying to get a Diamond Fire GL 1000 Pro AGP (with a VESA stereo port) to work with a pair of NuVision 60GX glasses. I've tried a bunch of different drivers (for NT 4.0 SP6a, which I think is …

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Re: Is there a DOS utility that can set CPU fan speed?

Posted on 2022-05-16, 22:03

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by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just got a molex to fan header adapter and the computer works!

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Is there a DOS utility that can set CPU fan speed?

Posted on 2022-05-15, 20:41

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have an ASUS P2B motherboard that seems to post just fine but reports an error in the CPU temperature sensor. The effect is that while it boots the CPU fan never starts (tested a few different CPUs and different fan headers on the board). I know there are windows utilities to set CPU fan speed but …

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Re: Help with 256 colors in CL VLB video card

Posted on 2022-03-02, 17:10

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It seems the CL win3.1 drivers all have the video issues. But I just tried the generic Super VGA driver and 256 colors at 640x480 is working great (tried it with a CD-ROM that has video, In The 1st Degree, and the playback speed seemed smooth so I don't think I'm missing out on any performance with …

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Re: Help with 256 colors in CL VLB video card

Posted on 2022-03-01, 23:34

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just tested Duke 3D in SVGA 640x480 mode and while slow (it's only a 486) it seems clean.

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Re: Help with 256 colors in CL VLB video card

Posted on 2022-03-01, 22:09

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Tried it with 640x480 8bpp testing full VRAM reliability and it didn't report any errors. I also tested the speed in case the error is showing up in some other way, though I don't know the values I should be expecting. I suppose my next step will be to try a different video card version.

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Re: Help with 256 colors in CL VLB video card

Posted on 2022-02-26, 06:35

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here is the same video card working with 16 and 16 million colors

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Help with 256 colors in CL VLB video card

Posted on 2022-02-26, 05:21

by

by sndtst

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a Cirrus Logic CL-GD5428 2 MB VLB Video Card in a 486 DX2 66 but for some reason when I set the video mode to 256 or 65,356 colors I get this strange artifact. The small lines disappear if the color depth is set to 16 or 16 million colors. Anyone have any ideas what is causing this?

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Re: Magenta Video on 3DFX Voodoo2

Posted on 2021-11-27, 20:33

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by sndtst

in Marvin \ Video

in Marvin \ Video

That thread was exactly what I needed! Thank you :) I tested the RGB pins on the RAMDAC and got values near the range that the fix thread OP said were out of range. In my case, my card uses a Texas Instruments TVP3409-135CNF RAMDAC which is proving hard to source. I haven't found if these chips are …

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Re: Magenta Video on 3DFX Voodoo2

Posted on 2021-11-25, 22:01

by

by sndtst

in Marvin \ Video

in Marvin \ Video

Located the right pins and about to setup a measurement harness but before I do I think I have a reliable test for what colors are having an issue.

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Re: Magenta Video on 3DFX Voodoo2

Posted on 2021-11-25, 21:38

by

by sndtst

in Marvin \ Video

in Marvin \ Video

Found this thread Voodoo 2 component map and now I'm going to try and measure the values.

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Magenta Video on 3DFX Voodoo2

Posted on 2021-11-25, 20:44

by

by sndtst

in Marvin \ Video

in Marvin \ Video

I have a Voodoo2 (Arcade/FXII with 8MB of RAM from Best Data) that seems to pass all of the diagnostics but when I launch a game I get a magenta hue on the video. In Tomb Raider it crashed after the 3DFX logo. I'm still trying to get a copy of Descent 2 which I had working on this card on a …

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