Editing CICS (section)

===Run-time conversion===
The '''Command-level-only''' CICS introduced in the early 1990s offered some advantages over earlier versions of CICS. However, IBM also dropped support for Macro-level application programs written for earlier versions. This meant that many application programs had to be converted or completely rewritten to use Command-level EXEC commands only.

By this time, there were perhaps millions of programs worldwide that had been in production for decades in many cases. Rewriting them often introduced new bugs without necessarily adding new features. There were a significant number of users who ran CICS V2 application-owning regions (AORs) to continue to run macro code for many years after the change to V3.

It was also possible to execute old Macro-level programs using conversion software such as APT International's ''[[Command CICS]]''.<ref>{{cite web|url=http://www.ibm.com/partnerworld/gsd/solutiondetails.do?solution=16478&expand=true&lc=en|work=[[IBM]]|title=Command/CICS|access-date=22 April 2018|archive-date=15 June 2021|archive-url=https://web.archive.org/web/20210615130438/https://www-356.ibm.com/partnerworld/gsd/solutiondetails.do?solution=16478&expand=true&lc=en|url-status=live}}</ref>