This video gives an in-depth look at what is currently the oldest known copy of 86-DOS, the antecedent to #MSDOS aka #PCDOS, where we go through the process of moving from CP/M, translating Z80 to 8086 code, and assembling it. Since this DOS predates the IBM PC, it must be simulated via #SIMH as a Gazelle with a Cromemco 4FDC controller.
#rretrocomputing