Remember: there used to be several levels of assembler: D, E, and F as well as H. D and E in particular had lots of restrictions on what MACROs and COPYs could do because of lack of memory. I believe D would run in a 64K real machine and E required 96K machine.
And to make matters sweeter you had to compile several operating system things on site in order to install a new release. So even operating system routines had to live with some of the limitations. I believe HLASM is based on the H level assembler with lots of changes. Lloyd ----- Original Message ---- From: Edward Jaffe <edja...@phoenixsoftware.com> To: IBM-MAIN@bama.ua.edu Sent: Tue, July 20, 2010 11:01:09 AM Subject: History of Hard-coded Offsets (Was: TSSO problems) Scott Rowe wrote: > 2) In OSWAITRC (the ESTAE for the OSWAIT TSO command), there is an NI >instruction to reset the wait bit in an AOF entry. The offset into the AOF >entry is hard-coded and ... I've seen other "old" programs with many hard-coded offsets and lengths and always wondered why this was such common practice back then. Was it because there were a lot of inexperienced assembler programmers writing code? Was it because people thought the platform would not last and treated every program as a "throw away"? Was it due to limitations in the assembler itself? -- Edward E Jaffe Phoenix Software International, Inc 831 Parkview Drive North El Segundo, CA 90245 310-338-0400 x318 edja...@phoenixsoftware.com http://www.phoenixsoftware.com/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
