Machine code monitor

A machine code monitor, which was often found in various 8-bit home computers, allowed the user to enter commands to view and change the memory of the machine directly, with options to load and save memory contents from/to tape or disk. Some full-featured machine code monitors gave the user detailed control of the execution of machine language programs (much like a debugger), and included absolute-address assembler and disassembler capability. It was not unheard of to do one's programming with such a monitor as the only editing tool.