ASSIST (the Assembler System for Student Instruction and Systems Teaching) is an
IBM System/370
The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path ...
-compatible
assembler
Assembler may refer to:
Arts and media
* Nobukazu Takemura, avant-garde electronic musician, stage name Assembler
* Assemblers, a fictional race in the ''Star Wars'' universe
* Assemblers, an alternative name of the superhero group Champions of ...
and
interpreter developed in the early 1970s at
Penn State University by Graham Campbell and
John Mashey
John R. Mashey (born 1946) is an American computer scientist, director and entrepreneur.
Career
Mashey holds a Ph.D. in computer science from Pennsylvania State University, where he developed the ASSIST assembler language teaching software. He wo ...
. plus
student assistants.
In the late 1960s, computer science education expanded rapidly and university computer centers were faced with a large growth in usage by students, whose needs sometimes differed from professionals in batch processing environments. They needed to run short programs on decks of
Punched cards
A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...
with fast turnaround (minutes, not overnight) as their programs more often included syntax errors. Once they compiled, they would often fault quickly, so optimization and flexibility were far less important than low overhead.
WATFIV was a successful pioneering effort to build a
FORTRAN compiler tuned for student use. Universities began running it in a dedicated "fast-batch" memory partition with a small run-time limit, such as 5 seconds on an
IBM System/360 Model 67
IBM mainframes are large computer systems produced by IBM since 1952. During the 1960s and 1970s, IBM dominated the large computer market. Current mainframe computers in IBM's line of business computers are developments of the basic design of th ...
). The low limit enabled fast turnaround and avoided waste of time by programs stuck in infinite loops.
WATFIV's success helped inspire development of ASSIST,
PL/C
PL/C is an instructional dialect of the programming language PL/I, developed at the Department of Computer Science of Cornell University in the early 1970s in an effort headed by Professor Richard W. Conway and graduate student Thomas R. Wilcox ...
and other student-oriented programs that fit the "fast-batch" model that became widely used among universities.
ASSIST was enhanced and promoted by others, such as
Northern Illinois University
Northern Illinois University (NIU) is a public research university in DeKalb, Illinois. It was founded as Northern Illinois State Normal School on May 22, 1895, by Illinois Governor John P. Altgeld as part of an expansion of the state's system ...
's Wilson Singletary &
Ross Overbeek and
University of Tennessee's Charles Hughes and Charles Pfleeger who reported in 1978 that ASSIST was being used in 200+ universities.
In the 1980s, NIU did a new implementation on IBM PCs, ASSIST/I (Interactive), used by computer scientist John Ehrman to teach a "boot camp" course in assembly programming at
SHARE (computing)
SHARE Inc. is a volunteer-run user group for IBM mainframe computers that was founded in 1955 by Los Angeles-area users of the IBM 701 computer system. It evolved into a forum for exchanging technical information about programming languages, ope ...
meetings, at least through 2011, but perhaps for several years after.
On March 1, 1998, Penn State declared that ASSIST was no longer
copyright
A copyright is a type of intellectual property that gives its owner the exclusive right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, educatio ...
ed and that the
program was
freely available as per the last release notes.
The original ASSIST code seems to still get some use, as seen in 2017 demonstration video assembling its source and running it in
MVS 3.8 emulation on a laptop.
IBM System/360 and /370 computers used
24-bit addressing and ignored the high-order 8 bits. Assembly programmers of the era, including those who wrote ASSIST, often saved precious memory by using the high-order 8 bits for flags, which required a compatibility mode when IBM introduced
31-bit
In computer architecture, 31-bit integers, memory addresses, or other data units are those that are 31 bits wide.
In 1983, IBM introduced 31-bit addressing in the System/370-XA mainframe architecture as an upgrade to the 24-bit physical and v ...
and then
64-bit
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A compu ...
addressing.
References
External links
ASSIST Introductory Assembler User's ManualASSIST - Assembler System for Student Instruction & Systems Teaching (IBM System /370 Reference Summary)Assist distribution archivemaintained by NIU's Michael Stack
{{DEFAULTSORT:Assist (Computing)
Interpreters (computing)
IBM mainframe software