Simple Tape Control Program

This document, M-1131, dated November 16, 1961, outlines the "Simple Tape Control Program" (TCP) for the PDP-1. The program enables operators to read (binary or BCD), write, space, and check magnetic tapes. It supports operations on one to three tape units, handles parity error detection, and provides mechanisms for continuous tape operation. The document includes a detailed calling sequence, a breakdown of command bits for specific tape operations, status bit descriptions, and a complete symbolic program listing with explanatory notes on its internal decision-making and timing subroutines.