PDP-8 Family Paper Tape System User's Guide

This document describes the Binary Punch program (DEC-08-YXYA-D), a utility for PDP-8 series computers (PDP-8, 8/S, 8/I, 8/L) released on October 1, 1969.

Purpose: The primary function of the program is to punch information from selected blocks of core memory onto binary-coded paper tape. It supports both high-speed and teletype punches (like the ASR-33).

Requirements:

• Storage: Occupies 75 decimal core memory locations.
• Equipment: A basic PDP-8 system with either a standard ASR-33 Teletype or a high-speed punch (PC03, PP8I, PP8L).

Usage & Operation:

1. The program is loaded into memory using the Binary Loader.
2. It cannot be called as a subroutine.
3. Operation involves a sequence of user inputs via the switch register and console keys (LOAD ADDRESS, START, CONTINUE):
   • The program's starting address (7465) is loaded.
   • The user then specifies the number of blocks to be punched.
   • For each block, the user inputs the initial and final memory addresses to be dumped.
4. The program punches a leader, then the specified data blocks, and finally a trailer.
5. It halts between inputs for the user to set the next parameters (number of blocks, initial/final addresses) and also after punching the last block.

Output Format: The generated paper tapes are compatible with the Binary Loader. Each block on the tape begins with a 2-character representation of its initial memory address, followed by 2-character groups representing the binary contents of each word. A 2-character checksum is appended to the end of each block. Data is processed by taking memory words, shifting the most significant half, punching it, and then masking and punching the least significant half.

Performance: Execution time for the program is limited by the speed of the output punching device.