On Tue, 20 Nov 2018 15:02:19 -0600, Paul Gilmartin wrote: >On Tue, 20 Nov 2018 20:13:35 +0000, Seymour J Metz wrote: > >>The ASCII bit in the PSW affected only the decimal instructions, including >>UNPK. >> >Doesn't UNPK just swap nybbles of the rightmost byte
It does do that. >and set all other >zone bits to 0 regardless of character set? No. It never sets the zone bits to 0. It sets the zone bits to F when in EBCDIC mode and to 5 when in ASCII mode. Don't forget ASCII was a 7-bit code. IBM was probably among the first to design an 8-bit extension. I don't know when an 8-bit ASCII standard was introduced. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
