[Coco] J&M/JDOS Manual

[Mark J. Blair]

I'm excited that I just received a J&M controller via eBay. I think it's the classic JFD-COCO, and the same model that I had on my first computer back in the early to mid 1980s. It's a bit banged up, but I opened it up to clean the contacts and dust it out, and gave it a very cursory test on my CoCo 3 plugged into an MPI. It seems to work, though I've read about compatibility problems with some (?) J&M controllers in the CoCo3, so I'll keep my eyes open for trouble.

I'm still interested in finding a fancy JFD-CP controller, but this one is a nice upgrade. It has a JDOS 1.11 ROM.

I recall that in addition to the normal RSDOS commands, there were extra commands in JDOS to allow use of 40 tracks and double-sided drives. Sometime in the past 30 years, I must have killed off the brain cells holding the details with one drink too many, so here I am asking for a memory refresh.

Is a scanned manual for JDOS available anywhere? I did some lazy googling and didn't turn one up. A quick summary of the JDOS-specific commands would probably tell me everything I need to know if the manual isn't online anywhere.

I notice that it lacks the normal keying slot on the floppy cable edge connector. I may get daring and Dremel in a keying slot, because I do like connectors to resist improper insertion.

-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/