IBM 7090/94 IBSYS Operating System
The IBSYS Operating System was supplied by IBM for the 7090/94 series. The system included a monitor program, the FAP assembler, FORTRAN II/IV, COBOL, and various utilities.
The FAP assembler was a modification of SAP (Symbolic Assembly Program) that was originally written by United Aircraft for the IBM 704 vacuum tube computer.
IBSYS Operating System Organization
| Input/Output Executor (IOEX) | Nucleus (IBNUC) | Supervisor (IBSUP) | Editor (IBEDT) | System Core Dump (SYSDMP) | |
|---|
| Utilities (DK90UT) | 9PAC Processor (9PAC) | Commercial Translator Processor (CT) | Input/Output Control System (IOCS) | Generalized Sorting System (SORT) | Restart Program (RESTART) | IBJOB Processor (IBJOB) | Symbolic Update Program (UPDATE) | FORTRAN II Processor (FORTRAN) |
|---|
| Utility Monitor | | Commercial Translator Monitor | | IBJOB Monitor | | FORTRAN II Monitor |
|---|
| Disk/Drum Utilities & Tape Dump | | Compiler, Loader, Symbolic Maintenance (MAIN), & Subroutine Updater (SUBUP) | | COBOL Compiler (IBCBC) | FORTRAN IV Compiler (IBFTC) | Macro Assembler (IBMAP), Loader (IBLDR), Subroutine Library (IBLIB), & Debugging Processor | | FORTRAN II Compiler & FAP Assembler (including IBSFAP) |
|---|
FAP and FORTRAN II could be used with either the IBM FORTRAN Monitor as an independent program or the same monitor as part of the 7090/94 IBSYS Operating System.
The Monitor was controlled with Control Cards that were identified with an asteric in column one.
An example Job Deck is:
*ID JOB NO. 3794 COZMIC (First Card in Job Deck -- Identified Beginning of Job)
* XEQ (...This Job is to be Executed...)
* FAP (Tells Monitor that Following Program is in FAP)
(FAP Source Deck -- Last Card is END)
FORTRAN (Tells Monitor that Following Program is in FORTRAN)
(FORTRAN Subroutine Source Deck -- Last Card is END)
FORTRAN
(FORTRAN Subroutine Source Deck -- Last Card is END)
DATA (Tells Monitor No More Source -- Data Follows...)
(Data Cards if Any)
The IBSYS operating system was a more comprehensive monitor that could run many different software packages depending on the needs of the current job. Control cards for IBSYS were identified by having a '$' in column one with a Control Name following immediately after the '$'.
An example Job Deck to run a FORTRAN program under IBSYS is:
$JOB (First Card of a job)
$EXECUTE IBJOB (Calls IBJOB Monitor that Contains the FORTRAN IV Compiler)
$IBJOB GO, (options) (Specified GO Execution Option in IBJOB)
$IBFTC DECK1 Options (Specified FORTRAM IV, Deck Name, and Compiler Options)
(Program Source)
$DATA (Data Follows)
7/8EOF (Last Card of a Job -- First Card Column has 7 and 8 punches :)
The IBSYS Operating System required eight tape drives with two channels in order to run.
If an IBM 1301 disc drive or a 7320 drum storage unit was available, then IBSYS could operate with only four drives. The FORTRAN Monitor alone (not part of IBSYS) required seven tape drives -- or six tape drives and a disc drive.
http://www.frobenius.com/ibsys.htm -- Last Revision: 23 August 2001
Copyright © 1996 - 2013 Jack Harper (unless otherwise noted)
