ISO Altos 686/886 documentation

[Al Kossow]

Worked on cleaning up and documenting the 686 and 886 I had over the weekend.
Pics and firmware up now on bitsavers, but I don't have any documentation. I'm
especially interested in the 8274 diagnostic serial port, which isn't installed
on either of my boards.

I'll have a hard disk image of Concurrent CP/M 4.1 for it up under bits/Altos/686
later today, just installing it now.

Also, the Xenix image from a 886 will boot on a 686. Turns out the disk in the 686
had a bad head, which is a drag because the image I made of it is missing heads 4 and 5.

I'm also still trying to figure out if there is any way to do an inital format since
at least the CP/M tools expect a config block on disk before you can partition it,
which optionally will format the disk (chicken and egg).