ASSIST (the Assembler System for Student Instruction and Systems Teaching) is an
IBM System/370-compatible
assembler and
interpreter developed in the early 1970s at
Penn State University
The Pennsylvania State University (Penn State or PSU) is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High School of Pennsylvania, Penn State became ...
by Graham Campbell and
John Mashey. plus
student
A student is a person enrolled in a school or other educational institution.
In the United Kingdom and most commonwealth countries, a "student" attends a secondary school or higher (e.g., college or university); those in primary or elementar ...
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 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). 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 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'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) meetings, at least through 2011, but perhaps for several years after.
On March 1, 1998, Penn State declared that ASSIST was no longer
copyrighted 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
Notable 24-bit machines include the CDC 924 – a 24-bit version of the CDC 1604, CDC lower 3000 series, SDS 930 and SDS 940, the ICT 1900 series, the Elliott 4100 series, and the Datacraft minicomputers/Harris H series.
The term SWORD is ...
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 vir ...
and then
64-bit 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