550 Micro-Magnetic Tape Control

This document provides a comprehensive technical overview of the Type 550 Micro-Magnetic Tape Control, which manages up to four Type 555 dual tape transports for PDP-1 and PDP-4 computer systems. The documentation details the tape format, the use of mark and timing tracks for data addressing, and the logic behind reading, writing, and searching operations.

Key contents include: * Operation and Programming: Descriptions of tape motion controls (Start/Stop delays), flag definitions (Data, Block End, and Error flags), and a list of PDP-4 instructions for tape control. * Transfer Operation Chart: A guide for programmers on how to handle tape flags during search, read, write, and move modes. * Technical Tips and Troubleshooting: A collection of field service memoranda addressing specific hardware issues, such as relay timing restrictions, motor grounding, and problems with block erasure. * Diagnostic Software: Documentation for various test programs, including the Micro Tape Data Test, Micro Tape Exciser, Micro Tape Format Pack, and Micro Tape Rocker Program.