For a more precise time frame on the introduction of IBM implementation of S/390 architecture using a combination of native hardware microarchitecture plus millicode, this reference agrees with my memory that it was generation 4 of the IBM CMOS processors.
https://en.wikipedia.org/wiki/Millicode The G1, G2, and G3 9672 processors were designed at the IBM Boeblingen lab, and I am not familiar with the underlying hardware microarchitecture of those machines. I do remember that that from doing problem diagnosis during MVS bring up on those machines that the term "microcode" was still being used. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY -----Original Message----- From: Jim Mulder <[email protected]> Sent: Tuesday, November 22, 2022 10:01 PM To: [email protected] Subject: Re: Storage protection keys My wife agrees with you that my "vaccine research" comment was over the top, and I am trained to accept her judgement on such matters of decorum, so I apologize for that. I agreed with you that processor designs of the XA/ESA era were as you described. The IBM 303x, 308x,and 3090 processors all implemented the 370, 370/XA, and 370/ESA instruction sets via microcode on top of underlying different hardware microarchitectures, which could be characterized as a form of emulation. And I agree that, for that era, your statement that "last HARDWIRED CPU was probably the S/360 & S/370 model 195" is correct. However, the facts are that the IBM Power processor chips and the IBM z processor chips are separate entities. IBM z/Architecture has never been implemented by IBM on IBM Power processor chips, other than a brief period where the zPDT software emulator had versions for both Power and x86 machines. The Power version was subsequently discontinued. For more than the past decade, a considerable number of the z/Architecture instructions have been implemented directly in hardware, with some others being cracked into multiple hardware ops, and some more complex instructions being implemented in millicode. If you want to think of the millicoded instructions as a form of emulation, I don't object. However, it is done on z hardware, not Power hardware. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY "My friends, you know me to be neither rash nor impulsive. I am not given to wild, unsupported statements." (Jor-El, "Superman", 1978, somewhat out of context) -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Paul Gorlinsky Sent: Tuesday, November 22, 2022 8:54 PM To: [email protected] Subject: Re: Storage protection keys Interesting that you have to resort to a childish rant ... So totally unprofessional ... BTW if you read the documents you proved they actually prove my point ... Dr. Gene Amdahl picked me to lead the design and build of his CMOS XA processor for a reason ... My direct OS and hardware experience... 52 years worth... Paul ---------------------------------------------------------------------- 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
