The combination of of such an assembler and debugger is a powerful one which can reduce by a factor of perhaps five the time required to write and debug a machine language program. For the latter the essential prerequisite is an interactive environment, in which the power of the computer is available at a console for long periods of time.

The necessary tools for this task are an assembler and a debugger. It is a sad fact, however, that a large number of these problems never run at all because of the inordinate amount of effort required to write and debug machine language programs. There are still many problems which must be coded in the hardware language of the computer on which they are to run, either because of stringent time and space requirements or because no suitable higher level language is available.

The problems of machine language programming, in the broad sense of coding in which it is possible to write each instruction out explicitly, have been curiously neglected in the literature.

Writing program in machine language is