BO — block transfer out
BO x
Transfer block of n words from MCM to an in-out unit where x is the initial address of the block in MCM, and ±n times 2-15 is contained in AC. The computer is stopped while the transfer is taking place. After the block transfer, AC contains the address which is one grater than the MCM address from which the last word was taken and stored; AR contains the initial address of the block in MCM.
BO | 00100 xxxxxxxxxxx |