OK, I can boot TRSDOS 2.3 and 2.7 via single density and double density DMK images, also with Percom and Radio Shack doublers. That code is checked in.

It's quite far from 'done' though; I have not implemented the read address (do I really need to?), read track, and write track commands. Those are necessary for formatting disks. I intend to, but I can punt on that a little while, I guess, by formatting disk images in another emulator (e.g. trs32). But the other stuff seems to work correctly. (Well, 'write sector' probably needs more thorough testing).

DMK only at this point. Maybe I'll do JV1/3 later, but it's not a priority for me relative to getting the other stuff working fer shur.

So, it's a start!