What you showed will do a STH of some register somewhere, but not necessarily R4. For it to be R4, you need another blank character after the IEFUJV, or else delete the AL1(7) byte, or change the CL8 to CL9, etc. Adding 3 more blank characters would allow this code to store R4 somewhere and then not skip over the execution of the next instruction after the IEFUJV eye-catcher.
Bill Fairchild -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Rick Fochtman Sent: Friday, August 19, 2011 1:56 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Last card reader? --------------------------------------<snip>--------------------------------- And I've had a few doozies - one program should have had an LA instruction that got keypunched as an LH; the error was discovered fourteen years later when IBM changed a control block around so the referenced field wound up on an odd boundary. ------------------------------------<unsnip>-------------------------------- This one took me 8 months to isolate: B 12(,R15) X'47F0F00C' DC AL1(7),CL8'IEFUJV' X'07C9C5C6E4D1E54040' Ended up doing a STH of R4 at what appeared to be a totally random address. Only failed when the clobbered storage was executed. :-) Our systems staff had its own sandbox to play, and test, all changes, but that guy's "under-confidence" was such that he wouldn't even test on our sandbox. Rick ---------------------------------------------------------------------- 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
