I remember learning that method from an assembler programmer I worked with. I can also remember poring over microfiche source code listings to get some of this information so maybe the information was not readily available from IBM in those days. The practice seemed to be fairly common in the early 1970s. That was in the day when systems programmers would hack something together to perform a required task and not worry too much about support as a better idea would always come along.
Then suddenly that was all wrong and we had to use the macro definitions for all offsets etc and write "structured" code. That happened (in my case at least) toward the end of the 1970s and probably coincided with the rise of commercial software development as well as the dreaded "standards" that were coming in. Probably it was just because things were becoming more "organized". David Elliot zSeries Software Support -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Edward Jaffe Sent: Tuesday, July 20, 2010 10:01 AM To: [email protected] 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 made one enhancement to TSSO years ago and got frustrated with it because there were so many hard-coded offsets and lengths. Every change I made seemed to break something else. I remember thinking, "this program needs a major cleanup/restructure to be maintainable"! 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 [email protected] http://www.phoenixsoftware.com/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] 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 [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
