MAINDEC-10 ReadBin

The MAINDEC 10 Read Binary Test Program is a utility designed to test the performance of the PDP-1 photo-electric paper tape reader during binary operation. It uses a closed loop of test tape containing alternating lines of six 1's and six 0's (represented in octal as 77 00 77 00...).

The program works by reading the test tape and comparing each bit of the incoming data against expected values stored in core memory. It specifically detects two types of reader malfunctions: "picking up bits" (reading a 1 where a 0 is expected) and "dropping bits" (reading a 0 where a 1 is expected).

Operation involves loading the MAINDEC 10 program tape, then the test tape loop. The system then reads the tape, pausing on errors to display the incorrect data in the AC and IO registers for diagnosis, and allowing the operator to restart. The program also supports various advanced diagnostics, including high-speed, brake, clutch, and multispeed tests, as well as margin checks on the reader's amplifiers and logic circuits to ensure proper voltage levels. An auxiliary program is available to generate the required test tape.