Ondisk-Offdisk

This document describes two DIAL-based programs, OFFDISK and ONDISK, designed for the PDP-12 computer system. These programs allow users to dump the contents of a DF/DS-32 disk surface onto a LINCtape as a protected binary file (OFFDISK) and subsequently restore those images back to a disk (ONDISK).

Key details of the document include:

• Functionality: The programs facilitate the management of multiple disk-oriented systems by allowing them to be stored on and interchanged via LINCtape. Up to five disk images can be stored on a 1600-block LINCtape.
• Operation: Both programs are interactive and use the display to prompt for the tape unit, disk unit, and file name. They include built-in error handling for disk and tape operations.
• Requirements: The system requires an 8K PDP-12, a VR-12 scope, a TU-55 tape transport, and a DF-32 disk.
• Technical Notes: The programs use memory locations 2000-6000 in Field 0 for storage and utilize all of Field 1 as a buffer. Modifications are required if the user wishes to utilize 1000-block formatted LINCtape instead of the standard 1600-block format.