Half Duplex Pseudo Teletype Service Routines

This document consists of the source code and symbol table for the PTYSRH program, which provides half-duplex pseudo-teletype (PTY) service routines. The document includes accumulator assignments, device-dependent I/O status bit definitions, and various subroutines for managing PTY device interactions such as input and output, initialization, and character handling. It also outlines the interaction with system components like TCOMM and provides a symbol table for the routines.