How is the ASCII bit relevant to teletypes? It only affects the handling of the sign nybble.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Robin Vowels <[email protected]> Sent: Saturday, August 8, 2020 11:40 PM To: [email protected] Subject: Re: Case Study: IBM SYSTEM/360-370 ARCHITECTURE (1987) ----- Original Message ----- From: "Steve Smith" <[email protected]> To: <[email protected]> Sent: Sunday, August 09, 2020 10:57 AM 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. What? See my earlier report that no IBM operating system could turn on the ASCII bit. The ASCII feature would have been useful in talking to ASCII teletypes. > 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), no? Look at page 57. ED, EDMK, TR, TRT, etc etc are all in this manual. See Bitsavers. > 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. It did. Both EBCDIC and ASCII. But, as I reported earlier, no IBM operating system permitted the ASCII bit to be set. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
