Bun's Lab – Telegram
Bun's Lab
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Electronics projects, vintæg computing, programming and repairs. A minimalist blog of sorts.
@BunsGarden @BunsNook
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I'm beginning to suspect a broken chipset. Cooling it down produces different codes
Blue is where the data lines from the RAM connect directly to the chip set. Red is the address and control lines, through the 74F244 buffers. No broken trace.
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Sometimes it does two or three passes before it arrives at 1312 and hangs. This behavior depends on the temperature of the IC.

I'll call it quits for today. Thinking about tossing it into the parts bin.
Reinstalling DOS on my XT, because it shot itself, again.
There we go. Quick and easy thanks to backups.
For those interested: here are the insides of my XT.
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It's sporting an 8 bit Ethernet card, an 8 bit Aztech SoundGalaxy soundcard, as well as an XT-IDE setup.
The XT-IDE ROM lives on the network card, it's configured to use a 16 bit IDE card in the XT's 8 bit bus. As long as you use an IDE device capable of 8 bit transfers, such as a CF card, this is perfectly fine and works.

On the right you can see the bare bones IDE card that I use. It was meant to provide a secondary IDE channel for CD-ROM drives in a time when these weren't standard yet. Hence why it has those two chinch connectors. They just route the drive's analog audio out to the back of the PC with no amplification even. There is barely anything on the card except for some buffers and logic.

The IDE bus originally was just the ISA bus in cable form.
Bun's Lab
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The clunky 20 Mb MFM drive is deactivated because it's way too loud for my nerves.
Usually the MFM controller card would throw an error, if the hard drive gets no power. However, I found a hidden jumper that was fixed with a jumper wire. I put a jumper header in instead. If unset, the controller too is deactivated. Which makes it possible to leave it in even if unused. Eventually I'll expand that into a switched configuration. Enabling me to turn the MFM portion of the system on and off as I please.

The XT-IDE can happily coexist with the MFM drive.
Here are the CPU and FPU.
The specs:
4.77 MHz 8088 CPU
Optional 8087 FPU
640kB of RAM
360k 5.25" floppy drive
20Mb Seagate MFM hard drive
Hercules graphics, 1 bit color depth
SoundGalaxy BX
Ethernet
2x Serial, 1x Parallel
128Mb CF card used by my hotrodded XT-IDE set-up
Ahh gee my network doesn't work.. time to troubleshoot.

Edit: of course it doesn't, this is the wrong net.bat file and the wrong packet driver too
Uhh yes.. I forgot all of those settings. Usually I write everything down and have a ton of backups. I just can't find it.