Executive programs

This classification distinguishes programs that are not specifically tailored to any one user program. Executive programs are general purpose programs related to the running of CSIRAC. There are several types of Executive programs. The most important executive program is the Primary & Control, essential for all programs. Another example is the Tape Symbol Print program, which makes it easier for the user to understand a program, which is done by encoding machine language instructions into symbols. A further example is the machine useage log program used for department analysis.

In later computer developments, executive programs would be incorporated into operating systems.

Machine test programs

This classification distinguishes programs that test the basic functions of the machine, such as memory performance, arithmetic operations, reader tests, drum performance, teleprinter and punch tests and the facilities needed for programs to operate.

In later computer developments, machine test programs would be incorporated into the operating system and performed automatically during booting.

Input routines

This classification distinguishes routines required for inputting data to the machines from 5 or 12 hole tape readers.

In later computer developments, input device drivers had a similar function.

Teleprinter and flexowriter output routines

This classification distinguishes routines that provide means for outputting information to the teleprinter or flexowriter.

In later computer developments, output device drivers had a similar function.

Mathematical routines

This more general classification distinguishes routines for various mathematical functions such as statistical, division, fractional powers, trigonometric functions, transcendental functions, double precision functions, floating binary functions, complex arithmetic and eigen vectors. This classification also includes programs such as matrix inversion, curve fitting, simultaneous linear equations and code conversion.

Music programs and data

These programs generating tones and data tapes would define factors such as frequency and duration.

Demonstration programs

These were mainly games.

Nuclear physics programs

These programs were written and used by the Physics Department of the University.


These programs and routines were written by users to solve particular problems. The History team is not familar with some of these programs.


This is an English language programming system.


There are some programs and routines whose content is covered by the above classifications but their content is unknown.



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