evasive wrote on 2021-04-28, 21:10:

First of all, my sincere condoleances. Please take your time to process the loss of your parent. From my personal experience, it does need time, give it time.

The new pictures have been added to the page. They are well worth the wait.

Thank you and stay strong.

Quite welcome, and thank you, evasive. The kind words are appreciated!

I figured I'd give another update, as I've made a few discoveries with this machine. First of, it's quite picky about what it wants to boot from.

None of my hand-spun boot disks would work with this machine, despite my Pentium rig working just fine with each one. (Maybe it has something to do with the DOS revision I'm using?) The only disks it will boot from are the original DOS reinstallation disks, and the TeleVideo diagnostics disk. (The latter seems to be a bad image, as many of the EXEs are corrupt.) So I used the diag disk to boot up the machine, then swapped in another 1.2MB disk with SpeedStor 6.5 copied onto it. SpeedStor actually runs on this machine, successfully reports the machine as an IBM AT running DOS 3.10, but it doesn't seem too happy with the disk controller at all.

https://drive.google.com/drive/folders/1gJudG … h5x?usp=sharing

Once SpeedStor loads, I get an "Unable to correctly establish drive types" error, and it defaults to a Seagate ST4077R for the first drive. When I manually specify the ST225, all the diagnostics options result in a "0x80 - Controller fails to respond" error. In fact, when I run the "Internal controller test" it gives me an "*ERROR* Controller failure" report.

I'm more inclined to assume there's something wrong with the controller card at this point. I don't see any ROM chips on the card itself, just a bunch of TTL logic chips and the like. (It appears to be a WD chipset for the drive controller portion.) If this wasn't the original controller card to the machine, that also happens to have the floppy controller integrated onto it, I'd have done a rip-and-replace by now.

Either way, it looks like I'm in the market for a new (to me) MFM controller card.