There are instructions like SIE that IBM no longer documents for the general public. There might be instructions for optional features that are not part of the architecture.
Back on the S/370 there were scads of instructions that were not part of the architecture and were documented in separate manuals; I'm not aware of any for Z. -- 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 Schmitt, Michael <[email protected]> Sent: Wednesday, June 18, 2025 11:39 AM To: [email protected] <[email protected]> Subject: Re: Is there an equivalent of an S-con for a long displacement? External Message: Use Caution On z/Architecture, are there instructions that the machine will execute that are not following the Principles of Operation documentation? Or would all such instructions get a specification exception? Here's I'm thinking of HP-41 Synthetic programming [https://secure-web.cisco.com/1ZbDP0lGBgv9zypLKJt_T9fljkaXMef-YUQF-UlzphICFeuZn1HaIeGLXz6HhP01eDvMA-UUAypnpjrEK87QHgNqBIoja4zBjAhdzkKEhR3IpgjPYoqiYzhs43x4tlUxYmQ20qpt8kqoPhnPDIEq9dKEdwXbMDwGN31329sV_cniYGx5uEIdkw3cMWTraxCtxXbmoNZc7806pFpfyeI8_In4pDIoFAgDcHy9ee6S3rmGHcFwuKTqbSfOnFunVwPNmX8vXupfAMxwIR_a8LNCqkaDQGx4J11CtTryY5miIVoqvi87AjAPy4BZKUOeSGvh5UoHDwgbPR_LybmU7-jJHt6FHG3pYM8kqETAhaykmIlFmmE-uzDEhNumsJlxxrBxWz-EWfadO6UyKC0u94N7kaJqfuSqzsKcqOfHMosYx1fA/https%3A%2F%2Fwww.hpmuseum.org%2Fprog%2Fsynth41.htm], where you could exploit bugs in the calculator to construct instructions that the calculator execute, but would normally not allow you to enter. -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Seymour J Metz Sent: Wednesday, June 18, 2025 10:28 AM To: [email protected] Subject: Re: Is there an equivalent of an S-con for a long displacement? No building of instructions. My solution allowed for a short read only parameter instead of a long code sequence. -- 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: Tuesday, June 17, 2025 5:40 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 Tue, 17 Jun 2025 20:55:23 +0000, Seymour J Metz <[email protected]> wrote: >You can't accurately predict risks when you make wild guesses about the use >case. Certainly my use case does not require a nonstandard calling sequence. The OP said he was using as part of the parmlist. In your case, were SCONs only used to build instructions instead of processing it as data? Was your use significantly simpler that the other standard solutions? ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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
