/ tape boot program to load and transfer
/ the next item on the tape.
/ entry is made by jsr pc,*$0
/ so return can be rts pc
bit $2,(r0)+ / rewind status
mov $-512.,(r0)+ / byte count
mov mtma,(r0) / bus address
mov $60003,(r0) / read 800bpi
mov $60013,-(r0) / backspace