IBM High Level Assembler

High Level Assembler or HLASM is IBM's current assembler programming language for its z/OS, z/VSE, z/VM and z/TPF operating systems on z/Architecture mainframe computers. There is also a version that runs on Linux, primarily intended for systems running on a z/Architecture system (this environment is sometimes referred to as Linux on IBM Z).

For a discussion of high-level assemblers in general, see High-level assembler.

Overview

HLASM was released in June 1992 replacing IBM's Assembler H Version 2.[1][2] Despite the name, HLASM on its own does not have many of the features normally associated with a high-level assembler, but does offer a number of improvements over Assembler H and Assembler(XF), such as labeled and dependent USINGs, more complete cross-reference information, and additional macro language capabilities such as the ability to write user-defined functions. While working at IBM, John Robert Ehrman created and was the lead developer for HLASM[lower-alpha 1] and is considered the "father of high level assembler".[4]

High Level Assembler Toolkit

The High Level Assembler Toolkit is a separately priced accompaniment to the High Level Assembler. The toolkit contains:[5]

  • A set of structured programming macros —
    • IF/ELSE/ENDIF
    • DO/ENDDO
    • STRTSRCH/ORELSE/ENDLOOP/ENDSRCH
    • CASENTRY/CASE/ENDCASE
    • SELECT/WHEN/OTHRWISE/ENDSEL.
  • A disassembler.
  • A "Program Understanding Tool" (re-engineering aid).
  • A Source XREF utility (cross-reference facility).
  • Interactive Debug Facility.
  • Enhanced SuperC (source comparison tool).

See also

Notes
  1. HLASM followed a SHARE requirement to incorporate Greg Mushial's enhancements[3] to Assembler H into the supported product.

References
  1. IBM Corporation. "IBM High Level Assembler and Toolkit Feature - Release History". Retrieved October 21, 2012.
  2. IBM Corporation (5 May 1992). "Announcement Letter 292-244: IBM HIGH LEVEL ASSEMBLER/MVS & VM & VSE". Retrieved October 21, 2012.
  3. Greg Mushial (July 20, 1983), "Module 24: SLAC Enhancements to and Beautifications of the IBM H-Level Assembler for Version 2.8", SLAC VM NOTEBOOK, Stanford Linear Accelerator Center
  4. "Guide to the John R. Ehrman collection". Online Archive of California. X5621.2010. Archived from the original on 2022-10-15. Retrieved 2022-10-15.
  5. IBM Corporation. "Toolkit Feature components". Retrieved October 21, 2012.
Wikibooks has a book on the topic of: 360 Assembly


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.