On Tue, 23 Oct 2012 19:03:25 -0500, Shmuel Metz (Seymour J.) wrote: >In <0461273688451840.wa.m42tomibmmainyahoo....@listserv.ua.edu>, on >10/23/2012 > at 07:56 AM, Tom Marchant <m42tom-ibmm...@yahoo.com> said: > >>I do see where it has, "The Pack instruction does not check >>zones, except in the rightmost byte..." It doesn't check the >>rightmost zone, but it does move it. Is that what you mean? > >The one that I'm thinking of was around for several >years and "simplified" the explanation in PoOps by claiming that the >instructions only operated on decimal data. That made it hard for them >to understand the code for translating between binary and hex.
I see what you mean. The book does have a simplified explanation of the instructions, and only mentions using them for for converting between zoned and packed decimal. I don't see where it claims that it is the only use for them, though. In any case, when I took an assembler class in 1969, we used two books, the student text and the Principles of Operation. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
