|
Assembler H runs on [[OS/360 and successors]]; it was faster and more powerful than Assembler F, but the macro language was not fully compatible.
Assembler H Version 2 was announced in 1981 and includes support for Extended Architecture (XA), including the <code>AMODE</code> and <code>RMODE</code> directives.<ref>{{cite book|last=IBM Corporation|title=MVS/Extended Architecture Conversion Notebook|year=1984|url=http://www.bitsavers.org/pdf/ibm/370/MVS_XA/GC28-1143-2_MVS-XA_Conversion_Notebook_May84.pdf}}</ref>{{rp|page=3{{hyp}}28}} It was withdrawn from marketing in 1994 and support ended in 1995. It was replaced by High Level Assembler.<ref>{{cite web|last=IBM Corporation|title=5668-962 IBM Assembler H Version 2 Release 1.0|date=20 December 1996|url=httphttps://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=dd&subtype=sm&appname=ShopzSeries&htmlfid=897/ENUS5668-962|accessdate=October 8, 2012|archive-url=https://web.archive.org/web/20210924192756/https://www.ibm.com/common/ssi/cgi-bin/ssialias?infotype=dd&subtype=sm&appname=ShopzSeries&htmlfid=897/ENUS5668-962|archive-date=24 September 2021|url-status=dead}}</ref>
===Assembler XF===
===High Level Assembler===
'''High Level Assembler''' or '''HLASM''' was released in June 1992 replacing IBM's Assembler H Version 2.<ref>{{cite web|last=IBM Corporation|title=IBM High Level Assembler and Toolkit Feature - Release History|url=httphttps://www-01.ibm.com/softwaresupport/awdtools/hlasmpages/ibm-high-level-assembler-and-toolkit-feature-release-history.html|accessdateaccess-date=OctoberJanuary 2119, 20122025}}</ref><ref name="hlasm-announcement-letter">{{cite web|lastpublisher=IBM Corporation|titletype=Announcement Letter letter|id=292-244: |title=IBM HIGHHigh LEVELLevel ASSEMBLERAssembler/MVS & VM & VSE|date=5 May 1992 |url=httphttps://www-01.ibm.com/commondocs/ssien/cgi-binannouncements/ssialias?infotype=an&subtype=ca&htmlfid=897archive/ENUS292-244&language=enus|accessdateaccess-date=OctoberJanuary 2119, 20122025}}</ref> It was the default translator for System/370 and System/390, and supported the MVS, VSE, and VM operating systems. As of 2023 it is [[IBM]]'s current [[Assembly language|assembler]] programming language for its [[z/OS]], [[z/VSE]], [[z/VM]] and [[z/TPF]] [[operating system]]s on [[z/Architecture]] [[mainframe computer|mainframe]] [[computers]]. Release 6 and later also run on [[Linux]], and generate [[Executable and Linkable Format|ELF]] or [[GOFF]] object files (this environment is sometimes referred to as [[Linux on IBM Z]]).<ref>{{cite book|last=IBM Corporation|title=High Level Assembler for Linux on zSeries User's Guide|year=2008|url=http://publibfp.dhe.ibm.com/epubs/pdf/asml1020.pdf}}</ref> While working at IBM, John Robert Ehrman<!-- 1935-2018 https://web.archive.org/web/20221015170120/https://oac.cdlib.org/findaid/ark:/13030/c8xk8mnr/ https://web.archive.org/web/20221015172646/https://www.forevermissed.com/john-ehrman/about https://www.linkedin.com/in/john-ehrman-8794b26b --> created and was the lead developer for HLASM{{efn|HLASM followed a SHARE requirement to incorporate Greg Mushial's enhancements<ref>{{citation
| title = Module 24: SLAC Enhancements to and Beautifications of the IBM H-Level Assembler for Version 2.8
| author = Greg Mushial
...
</syntaxhighlight>
}} <code>USING</code> statements, a list of <code>USING</code> statements currently active, an indication of whether a variable is read or written in the cross-reference, and allowing mixed-case symbol names.<ref>{{cite webname="hlasm-announcement-letter" />
| title = IBM HIGH LEVEL ASSEMBLER/MVS & VM & VSE
| id = 292-244
| date = May 5, 1992
| url = http://www.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&htmlfid=897/ENUS292-244&language=enus
| work = Announcement letters
| publisher = IBM Corporation
| accessdate = October 8, 2012
}}
</ref> The <code>RSECT</code> directive (Read-only Control Section) allows the assembler to check reentrancy on a per-section basis. <code>RSECT</code> was previously "undocumented and inconsistently implemented in Assembler H."<ref>{{cite book
| title = IBM High Level Assembler for MVS & VM & VSE Release 2 Presentation Guide
| 