Burroughs Algol at Stanford University, 1960–1963

The decade between 1955 and 1965 brought a revolution to academic computing, both technologically and socially. As core memory replaced electrostatic memory and transistors replaced vacuum tubes, computers advanced from flakey and difficult-to-maintain devices to reliable appliances. At the same time (and partially as a consequence), the academic use of computing expanded rapidly, computing centers became increasingly essential facilities on every campus, and computer science began to gain acceptance as a legitimate academic discipline. This Anecdote recounts my experience during this dramatic shift in academic computing at Stanford University during the period between 1960 and 1963. At Stanford, this shift was driven by a remarkable Algol-58 compiler for a Burroughs 220 computer system.

B220 and BALGOL Come to Stanford

In 1960, Stanford replaced an overloaded IBM 650 with a Burroughs B220 computer system.¹ The B220 was a transitional machine, a vacuum-tube machine that performed base-10 arithmetic at a time when transistorized binary mainframes were being released.² Although the B220 system was only a modest commercial success (roughly 55 were sold),³ its influence was amplified by the popularity of the hardware and software among academic users.⁴ In addition to Stanford, the Stanford Research Institute, Caltech, Cornell, Georgia Tech, and Case used B220s.

The primary programming tool on Stanford’s B220 was the Burroughs Algebraic Compiler, or BAC.⁵ This technically advanced compiler implemented an Algol-58 superset called Burroughs Algol, or more commonly, BALGOL. For reasons I explain here, I believe that BALGOL played a central role in spreading computing at Stanford and beyond. In addition, the BAC design and implementation represented remarkable technical achievements, as we will see. Finally, BAC development played an important role in the subsequent design of the B5000 computer architecture.^6,7

The BALGOL compiler on the B220 was well suited for an academic environment, where computing load was dominated by program development and by nonprofessional programmers. Although the B220 was a relatively slow machine,⁸ the BAC was fast, compiling BALGOL source at nearly card reader speed. The BAC was also user friendly (despite the character set limitations of the keypunches of the day), and it implemented many user-oriented features, such as formatted I/O, debugging facilities, and a linking loader for easy incorporation of machine-language modules.

BALGOL on the B220 provided a highly accessible and useful computing service for the Stanford community. It was used for a variety of applications from many departments, including mathematics and statistics, physics, mechanical engineering, modern European languages, industrial engineering, and the Stanford Medical School. Professor George Forsythe employed BALGOL to implement automatic grading of student programs.

Building Computer Literacy at Stanford

The speed and user friendliness of the BALGOL compiler had a major impact on the penetration of computing into academia at Stanford. The Computer Center staff wrote a simple operating system that provided continuous compile-load-and-go operation on BALGOL jobs stacked in the card reader. This supported a batch-processing computer service with high job throughput, despite the slow machine. This fast service enabled Stanford numerical analyst George Forsythe to build a community of computer-literate students and faculty. He ran regular noncredit BALGOL programming classes that were attended by students, staff, and faculty. Nobelist Joshua Lederberg was among the students in one BALGOL class. Forsythe’s success in computer evangelism at Stanford was described in an article by Bob Forest in Datamation,⁹ the leading computer trade journal at that time. Forest wrote,

Forsythe also points out that BALGOL is easy to teach. The Computation Center conducts 10-hour BALGOL programming courses . . . So far, 10 such courses have been offered to some 300 students. The Computer Center also offered a special pre-school course to 50 members of the engineering faculty this fall.

A feeling of excitement permeated the Computer Center. Publication of the Algol 60 report 10 caused much discussion in Encina Hall involving faculty, students, and staff. The intellectual pot was further stirred when Richard (“Dick”) Hamming from Bell Laboratories spent a year-long sabbatical at Stanford. Hamming gave public lectures to the Stanford community on the social and technical impact...