> The PC instruction is a replacement for SVC. That's one use case. What about privileged code that scheduled an SRB into another address space and waited for a cross-memory post? A PC is potentially much less overhead.
> Both instructions exist solely to run authorized programs in other address > spaces. How did you run programs in another OS/360 address space. I don't see any time machines here. ;-) > If I remember correctly, You do; no SVRB, just a stack entry. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Jon Perryman <jperr...@pacbell.net> Sent: Thursday, August 29, 2019 12:22 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Assembler :- PC Instruction The PC instruction is a replacement for SVC. Both instructions exist solely to run authorized programs in other address spaces. PC was designed to fix and simplify many of those problems with SVC. Some of the important problems addressed (not all): 1. 256 static defined SVC's replaced by dynamically assigned PC token that are fully under the products control without sysprog intervention (e.g. SVC table def). 2. SVC SRB replaced by simple xmem implementation that occurs automatically. 3. Abend recovery easily implemented in PC routine. 4. Eliminates the need for programs in CSA or SQA. PC routines should run as fast (probably faster) as an SVC. If I remember correctly, > If I remember correctly, PC's don't have an RB and use the linkage stack instead. Jon. On Wednesday, August 28, 2019, 09:23:28 AM PDT, Seymour J Metz <sme...@gmu.edu> wrote: I doubt that PC was ever intended as a replacement for, e.g., BASR. How does its performance stack up against SVC? ---------------------------------------------------------------------- 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
