Originally Posted by shattered
With a bit of hackery, mc1502 how has diskette I/O. This machine had the usual cloned MS-DOS (nee Sigma-Four DOS) and something original called OTS (One Track System), for low-memory (128K) machines. DOS runs, OTS boots but hangs.

Apparently, all existing dumps of OTS are bad -- there were extra tracks on original disks and boot loader is looking for them.