Packed Unsigned was primarily used to save record space in the CPCS system and keep The CPCS check record to 40 bytes. Back then when your processing 2 million checks Every night. CPCS would literally be prioritized just below VTAM to get its work done Over the complaints of the MVS Support team. They were reminded that this is a Commercial bank and not their machine
-----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of billog...@optonline.net Sent: Friday, May 2, 2025 8:55 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Packed decimal sign nibbles >Hmm, if you don't want a sign, why have an 'S' in the PICTURE clause? >Signed: > 05 SIGNED-ITEM PIC S9(x) COMP-3. >Unsigned: > 05 UNSIGNED-ITEM PIC 9(x) COMP-3. Not being a COBOL speaker and not using packed decimal in other than trivial ways over the past 59 years (since my first S/360), this discussion has been very interesting. It would appear that there is considerable interest in the details of the topic. A short paper on the topic, exploring the details mentioned over the last week or so, would find many readers. It could touch on the actual machine instructions used in various cases, anything relating to "newer" instructions, performance, decimal data viewed in hex, date fields, options, zoned decimal usage, etc, etc. (In the old days this might have been a small IBM RedBook or something similar). Bill Ogden ________________________________ ---------------------------------------------------------------------- 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
