On Wed, 11 Jan 2023 10:38:09 -0600, Paul Gilmartin <paulgboul...@aol.com> wrote:
>how much is concealed behind the seemingly innocuous "formed from". I would say that nothing is concealed. If you look at the ESA/390 PSW and the z/Architecture PSW, the transformations are pretty obvious. Most of the bits are the same. Bit 12 is different. It is 1 for ESA/390 and 0 for z/Architecture. z/Architecture adds another AMODE bit and extends the instruction to 64 bits. >How much compatibility does this provide with pre-z code that manipulates PSWs? 100% compatibility. The 64-bit PSW accepted by LPSW is an ESA/390 PSW. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
