AFAIK, the CP component of z/VM still uses DIAG as a hypervisor call, although the repertoire of functions has greatly expanded since CP-67.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Jon Perryman <[email protected]> Sent: Wednesday, June 18, 2025 11:03 PM To: [email protected] <[email protected]> Subject: Re: Is there an equivalent of an S-con for a long displacement? External Message: Use Caution On Wed, 18 Jun 2025 11:22:08 -0500, Paul Gilmartin <[email protected]> wrote: >Diagnose? I believe its existence is documented; otherwise, "model dependent". >And no mnemonic. Ask yourself why DIAGNOSE does not use SCONs. DIAGNOSE used to be a pseudo instruction that was processed by VM CP exception handler. SCONs should be processed by hardware instead of software. Is there now an actual instruction? My favorite is the XDC 00DEAD00 pseudo instruction generated by the DIE macro. As an FYI, opcodes are part of the instruction language. All CPU (x86, RISCV, IBM z, ...) decode instructions during the decode phase. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
