On 9/7/20 6:18 PM, Fred Cisin via cctalk wrote:
Floppy boot seems like the next step.
OK, it boots off a DOS 3.3 floppy if that floppy is inserted before it attempts to boot from the hard disk. If I wait for it to do its "system file not found" bit, followed by a subsequent prompt to insert boot media and press a key, it attempts to access the floppy drive but then goes off into la-la land. Odd.
But anyway, taking the successful floppy boot route, I can certainly access the hard disk in terms of bringing up directory listings and TYPEing files to the display. So far, attempts to run anything from the drive just result in a lock-up (keyboard immediately unresponsive, hard reset required). There appear to be DOS utils on the drive, and command.com, but I've not checked for hidden system files yet. fdisk shows the partition as active.
Got an IBM "Advanced Diagnostics" floppy to try?
No, but I see that the minuszerodegrees site has an image, so I'll write that out and see what happens.
Looking at the drive contents, incidentally, I didn't see anything that explains (or interacts with) that unusual video hardware - it basically just holds DOS and a bunch of documents written by the original owner. Maybe they got suckered into buying this fancy graphics hardware without having any actual need for it, and then of course EGA and VGA came along and rendered it obsolete anyway.
XT controllers tended to NOT be interchangeable, even between various OEMs of Xebec!
Yes - something that people often seem to forget, too. I've run into that quite often, where someone will hang onto an old drive because of the contents, but they'll dump the controller that it was formatted against.
I don't know what the incompatability was.
I don't think there was any kind of standard at all for what the low level looked like - vendors were free to do what they wanted in terms of what values they used for flags and how they actually ordered things within the sector header. I suppose there were some tweaks made over time for optimization or reliability (or at least, recovery) reasons, too, which is why even a single vendor had a few different incompatible formats.
I expect it was the same in the SCSI and IDE worlds, but of course with those "the controller" which handles formatting is really part of the package, so it wasn't an issue.
Jules
