Dead programmes for a magnetic drum automatic computer

Summary

In an automatic computer with a memory for both numbers and instructions a mistake in an instruction sometimes causes a complete breakdown of the programme. In a machine with a memory having permanence these breakdowns can be prevented by blocking a part of the memory for writing. Standard sub-programmes which occur frequently can be placed in this dead part of the memory. These programmes require a special treatment of instructions which are changed by the programme itself. A description is given of a method for storing the return instructions in a hierarchy of subprogrammes, and of a technique for using variable instructions in a dead programme.