TED (Tape Editor)

This document serves as a technical manual for TED (Tape Editor), a software program designed for the PDP-12 system. TED enables selective modification of any specified block on tape or disk via a CRT display and simple keyboard commands. It displays ten memory locations at a time, allowing users to make both single-digit and multi-word changes using a movable cursor and various keys.

The program requires a PDP-12 system that supports DIAL-MS and is loaded using DIAL-MS I/O routines after system initialization. Upon startup, an initial question-and-answer (QANDA) frame prompts the user to specify the desired block and unit numbers. Once a block is loaded, its contents are displayed in octal format alongside their 6-bit ASCII equivalents.

Users can navigate the displayed content and edit digits using keys like SPACE, RUBOUT, RETURN, and ALTMODE. Additional commands (e.g., CTRL/F, CTRL/B, LINEFEED + S) allow moving the display window, searching for specific data, rereading the current block, writing changes back to the storage device, or navigating to previous/next blocks. The document also outlines the program's core memory layout, internal display control mechanisms, and assembly instructions using the DIAL Assembler.