ED was not part of the original S/360 instruction set? Did you look under Decimal Instructions?
Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Steve Smith Sent: Saturday, August 8, 2020 5:57 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Case Study: IBM SYSTEM/360-370 ARCHITECTURE (1987) The ASCII feature of S/360 probably wasn't used because it's nearly useless. Turning on ASCII mode caused PACK & CVD to generate ASCII sign codes and UNPK to generate ASCII zone codes. As far as I can tell, that's it. I'd say that the much later PKA & UNPKA instructions make a lot more sense than a system option, so I suppose somebody thinks the function is useful. But you could always convert zoned decimal with NC/OC or, of course TR. ED isn't in my very old S/360 PoOp (A22-6821-0), but ED certainly came out soon, long before the ASCII bit was officially dropped. Anyway, I don't know whether it supported ASCII mode or not. sas
