IBM 7090/94 IBSYS
| Company type | Operating system |
|---|---|
| Industry | Computer software |
| Predecessor | FORTRAN Monitor System (FMS) |
| Founded | 1960 |
| Founder | IBM |
| Products | IBSYS operating system, IBJOB processor |
| Parent | IBM |
IBSYS was a tape-based operating system developed by IBM for use on its IBM 709, IBM 7090, and IBM 7094 mainframe computers, along with a separate but related variant designed for the IBM 7040 and IBM 7044. This system evolved from the FORTRAN Monitor System (FMS) and appears to have been influenced more by Bell Labs' "BESYS" than by the SHARE Operating System.
The IBSYS environment accommodated a range of legacy language compilers and assemblers through the use of the $EXECUTE control card, supporting tools such as 9PAC, FORTRAN, and IBSFAP. In contrast, more recent language processors were managed via the IBJOB component.
For the IBM 7040/7044 machines, IBM later introduced similar operating systems identified as IBM 7040/7044 Operating System (16K/32K) 7040-PR-150. Additionally, IBM provided an operating system for the IBM 1410 and IBM 7010 systems called IBM 1410/7010 Operating System 1410-PR-155.
IBSYS System Supervisor
The IBSYS System Supervisor functions as a resident monitor that processes control card images inserted between program and data card decks within each job. Control cards for IBSYS start with a "$" symbol in the first column, followed by a Control Name which directs various IBSYS utility programs to configure and execute the job. These card decks were generally read from magnetic tape media prepared offline rather than directly from punched card readers.
IBJOB Processor
Operating under the IBSYS System Supervisor, the IBJOB Processor interprets control cards to initiate tasks such as compilation and program execution. It supports programming languages including COBOL, Commercial Translator (COMTRAN), Fortran IV (IBFTC), and Macro Assembly Program (IBMAP).
See also
Further reading
- Noble, A. S. Jr., "Design of an integrated programming and operating system," IBM Systems Journal, June 1963. This article explores the architecture and job management approach of IBSYS/IBJOB.
- "IBM 7090/7094 IBSYS Operating System Version 13 System Monitor (IBSYS)"
- "IBM 7090/7094 IBSYS Operating System Version 13 IBJOB Processor"
- "IBM 7090/7094 IBSYS Operating System Version 13 IBJOB Processor Debugging Package"
External links
- IBM 7090/94 IBSYS Operating System, Jack Harper
- Dave Pitts' IBM 7090 support
- Archived IBSYS source at Bitsavers
- History of FORTRAN and FORTRAN II – Software Preservation Group at the Computer History Museum, detailing FORTRAN II and related software running on IBSYS