FOIL— a file-oriented interpretive language
John C. Hesselbart, The University of Michigan, Ann Arbor, Michigan

In the summer of 1967 a project was begun at The
University of Michigan to provide users of a generalpurpose,
time-sharing system with the capability for
exploring conversational uses of computers for instruction.
The idea for the project developed from the
interest of faculty members in a number of subject
areas who wished to develop conversational programs
and investigate the benefits of computer-assisted instruction
in the classroom and laboratory using existing
time-sharing facilities. Support was provided by UNIVAC
Division of Sperry Rand Corporation.

 . . .

FOIL (File-Oriented Interpretive Language) was devel-
oped to provide conversational lesson-writing capability
for potential instructional programmers who have access
to a general-purpose, time-sharing system. Programs
written in FOIL reside on direct-access files and are
processed by an interpreter written in FORTRAN.
The interpretive mode places few constraints on the
syntax of the language and a number of beneficial
features are achieved.

 . . .

The source code for the processor is relatively machine
independent and therefore easily adapted to other
time-sharing systems. FOIL was originally implemented
on an IBM 360/67 computer operating under the
Michigan Terminal System. James Ruddell at the University
of Maryland readily adapted the processor for
the UNIVAC 1108 system and added capability for
lesson building and editing.

 . . .