Cafeteria Style Computing
Cafeteria Style Computing
Friday, April 12, 2024

Cafeteria Style Computing

by Charlotte Wipp

The Red Room

The Red Room, previously in the Mathematics and Computing building, was surrounded by lecture and study halls. The room itself could not be accessed by students, giving it a ‘temple’ like existence, housing computer operating priests. The Red Room existed to provide students and staff at the university with the chance to work with computers and learn how to program. Although, with the influx of student programs, the Red Room compilers were unable to keep up with the amount of computing jobs demanded each day. 

System/360 75

In 1967 Waterloo installed the IBM System/360 75 to increase the job capacity for education, research, and University administration. At the time the System/360 75 was the most powerful computer in Canada and was bough under the pretense of being ‘furniture’ to subsidies the cost. The compiler ran within the Red Room on the program WATFOR and later WATFIV. The Waterloo originating programs were based on Fortran and written for the System/360 75.  

Currently the IBM System/360 75 exists in the Computer Museum. 

Cafeteria Style Computing

The solution to the job-handling problem, was a dedicated terminal system. The system was enacted in a cafeteria-style service where students would line up to input their codes and wait for the output from compilers in the Red Room. 

The System/360 75 memory was linked to an express terminal, consisting of a 1000 punch cards per minute reader and a 1100 line per minute printer. In addition to the WATFOR and WATFIV compilers, the system could process jobs at 20,000 program statements per minute. The Computing Centre was able to process around 5000 to 7000 jobs per day with the Cafeteria Style Computing method.  

Students had access to systems, like the System/360 75, that could compile, read, and interpret their work in 1 to 2 minutes. A student would begin a job by submitting their Fortran source code on a deck of punch cards. A Fortran compiler built into the computer’s memory would process the source code line by line, translating it into a machine-readable object code file. The object code and additional software would be combined through a linker, a system program that combines many files into an executable file. Finally, with this file made of the data from the original source deck, the system would execute the program. Once finished, the computer would continue to the next job, an error in code causing the job to end immediately.  

IBM System/360 75

System/360 75

University of Waterloo Library. Special Collections & Archives. Dr. Donald D. Cowan Fonds. GA165-179_008.

The Punch card reader is on the right in the first image, and the printer is on the right side of the closest counter in the second photo. 

About the author

Charlotte is a Physics and Astronomy student currently in her 2B term at Waterloo. She enjoys tinkering and creating all forms of art in her free time. She works at the Computer Museum as their current Winter 2024 coop student.