The Reader/Sorter - MICR Task is the task that created the 40 byte record in ASM
-----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Steve Thompson Sent: Monday, April 28, 2025 2:02 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Packed decimal sign nibbles Guilty of CPCS which was done in COBOL. I don't remember having unpacked sign issues. Are you thinking of SCI code? I got a chance to look at it a bit but never did the programming for it (control of check sorters). Steve Thompson On 4/28/2025 12:56 PM, Steve Beaver wrote: > Did anyone work on CPCS and every number was packed unsigned to save space > > > > > ---------------------------------------------------------------------------- > ---- > > This electronic mail (including any attachments) may contain information > that is privileged, confidential, and/or otherwise protected from disclosure > to anyone other than its intended recipient(s). Any dissemination or use of > this electronic email or its contents (including any attachments) by persons > other than the intended recipient(s) is strictly prohibited. If you have > received this message in error, please notify us immediately by reply email > so that we may correct our internal records. Please then delete the original > message (including any attachments) in its entirety. Thank you > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Paul Feller > Sent: Monday, April 28, 2025 11:51 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Packed decimal sign nibbles > > Interesting... I was always under the impression that anything other than > x'0C', x'0D', and x'0F' was to be treated as invalid. That is basically how > I learned it in the mid 1970s when I took programming classes in college. > > Never having really looked that deeply in the Principles of Operation > (SA22-7832-13) manual I see chapter 8 (Decimal Instructions) goes for 13 > pages. > > Paul > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > Schmitt, Michael > Sent: Monday, April 28, 2025 11:33 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Packed decimal sign nibbles > > Same here: F A C E are positive, B & D are negative. > > The machine doesn't have an "unsigned" packed sign nybble. It is either > positive or negative. So "F" is positive as a sign nybble, or it is the > "zone" in other positions in a zoned decimal number. > > "F" is unsigned, however, in IBM Enterprise COBOL for z/OS: when you compile > with NUMPROC(PFD) it is *very* strict: there are only three valid signs: > > C: positive > D: negative > F: unsigned > > If all your code has preferred signs then it can generate more efficient > code, by using CLC and MVC for example instead of packed decimal > instructions. > > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > Phil Smith III > Sent: Monday, April 28, 2025 11:26 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Packed decimal sign nibbles > > Ok, well, in 1975 I was still in high school and playing games on VM over > dialup, didn't start my mainframe career until 1980. But the question > stands: what's with these "unpreferred" values? Why would they even exist/be > valid? > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > Lennie Bradshaw > Sent: Monday, April 28, 2025 12:21 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Packed decimal sign nibbles > > That's exactly as I was taught in about 1975. > Lennie > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > Phil Smith III > Sent: 28 April 2025 17:17 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Packed decimal sign nibbles > > A friend asked me about packed decimal sign nibbles, specifically x'0F'. I > said "Unsigned" was what I'd always been told. He said he was finding varied > answers, and then pointed me at SA22-7832-03 (PofOp, but an old version from > 2004) where, on page 8-2 (PDF page 1150) is the following table. It displays > correctly in monospace font, so hopefully you can read it: > > Recognized As > Code > (Binary) Digit Sign > -------- ------- ------- > 0000 0 Invalid > 0001 1 Invalid > 0010 2 Invalid > 0011 3 Invalid > 0100 4 Invalid > 0101 5 Invalid > 0110 6 Invalid > 0111 7 Invalid > 1000 8 Invalid > 1001 9 Invalid > 1010 Invalid Plus > 1011 Invalid Minus > 1100 Invalid Plus (preferred) > 1101 Invalid Minus (preferred) > 1110 Invalid Plus > 1111 Invalid Plus (zone) > > X'0A'? X'0B'?? X'0E'??? I'd only ever heard of x'0C', x'0D', and sometimes > x'0F'. Is it just me? I certainly don't claim to be Mr. Packed Decimal, but > I have encountered it off and on over the last 45 years, so I was very > surprised. > > I do see the discussion of "zones" in that section of the book, but that > doesn't clarify for me because zones have always been a mystery to me--never > needed to grok them. And it still doesn't explain the other values. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email > to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email > to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email > to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email > to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Regards, Steve Thompson ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
