Teletype Output Package

This document details the "Teletype Output Package," a set of subroutines for the PDP-7 computer, dated January 7, 1965. The package enables users to type individual characters, groups of three characters, or strings of characters on a teleprinter. It includes various formatting routines such as carriage return (TCR), space (TSP), tab (TYT), and a teleprinter initialization routine (TIN). A fundamental requirement for using this package is that the user must supply their own OTY subroutine to perform the actual single character type-out, with examples provided for both interrupt-driven and non-interrupt program environments.

The routines typically assume character codes are 6-bit, consisting of a 5-bit Baudot code and a 1-bit case indicator (upper/lower). While Type 28 Teletypes benefit from the package's automatic case tracking and adjustment, users are cautioned that direct keyboard input might alter the teleprinter's case unknowingly, potentially causing output issues. For KSR33 teleprinters, the 5-bit codes are translated to 8-bit Type 33 (ASCII + 200), and case shifts are not applicable. The document also provides a program listing of the subroutines.