Among Dijkstra's possessions is the booklet of the 1961 Western Joint Computer Conference which was held in Los Angeles. The booklet contains the abstracts of the presented lectures, including:
- J. McCarthy's `A Basis for a Mathematical Theory of Computation' and
- R.S. Barton's `A New Approach to the Functional Design of a Digital Computer'.
The abstract of the latter paper is briefly discussed here because it may help us understand how ALGOL 60 influenced hardware design in the USA during the early 1960s.
Barton's paper seems to have had two contributions. First, he scrutinized the existing methods of determining the functional design of a computer. Second, and more importantly, he seems to have proposed what was later called the stack machine. In his words:
[The new approach] is illustrated by explaining, in abstracted form, part of the control organization of a new and different machine based, in part, on the ALGOL 60 language. The concepts of expression and procedure lead directly to use of a Polish string program. A new arrangement of control registers results which provides for automatic allocation of temporary storage within expressions and procedures and a generalized subroutine linkage.
In short, ALGOL 60 may not have been used much as a programming language in the USA compared to Europe, but it nevertheless was an influential language on both continents (not to mention the U.S.S.R. and Japan).