M-1105 Apr61

This interoffice memorandum from April 1961 describes PRIM (Punch Read In Mode Tape), a routine designed to punch information from specific sections of core memory onto tape in "Read In Mode Format."

Users interact with PRIM via the console typewriter, starting the routine at memory locations 7400 or 7477. To use it, one types a starting address, a space, an ending address, and a carriage return (e.g., aaaaspbbbbcr). The routine then punches the data from the specified range. After each punch, it awaits further address ranges. To terminate the process, the user types an octal instruction (either a halt like 760400 or a jump like 60aaaa) followed by a period, which signals the end of input, punches a final leader, and halts the routine.

Special notes indicate that leading zeros can be omitted in typed addresses and that the routine provides basic error correction for mistyped input strings. The PRIM routine was supplied by Charles W. Adams Associates, Inc.