6 ms·

Depends where you look. Hard to see IBM's z/Architecture dying out in that timeframe (the latest branding for S/360-derived mainframes), for example, and the e

by rst 6y ago

Depends where you look. Hard to see IBM's z/Architecture dying out in that timeframe (the latest branding for S/360-derived mainframes), for example, and the embedded space is likely to remain an odd bestiary for quite some time.

monocasa 6y ago
Embedded is going to become way less of a bestiary, at least in the five digit gate count RISC space. ARC, Xtensa, V850, arguably MIPS, etc. all worked in the "we're cheaper to license than ARM, and will let you modify the core more than ARM will" space. I'm not sure how they maintain that value add when compared to lower end RISC-V cores. I expect half of them to fold, and half of them to turn into consulting ships for RISC-V and fabless design in general.
projektfu 6y ago
Isn't z/Architecture just emulated on top of POWER? That's been my impression for a while.
- monocasa 6y ago
  They share RTL, but it's not just a POWER core with a z/Arch frontend.
- dfox 6y ago
  You probably mean "TIMI" which is the user-visible ISA of IBM's "midrange" systems (ie. AS/400 or System/i) which was from the start meant as virtual machine ISA that is then mostly AOT transpiled into whatever hardware ISA OS/400 or i5/OS runs on. z/Architecture (S/360, ESA/390, what have you...) is distinct from that and distinct from PowerPC. Modern POWER and z/Architecture CPUs and machines are somewhat similar when you look at the execution units and overall system design, but the ISA is completely different and even the performance profile of the mostly similar CPU is different (z/Architecture is "uber-CISC" with instructions like "calculate sha256 of this megabyte of memory").
  - monocasa 6y ago
    No, they're probably talking about how modern z/Arch and POWER cores share a lot of HDL source these days.
    - projektfu 6y ago
      Yeah, I figured that most of the previously microcoded CISC instructions were basically software at this point.
      - monocasa 6y ago
        What's probably closest to the truth is that they have a very similar set of micro ops that they both translate to internally.
  - chx 6y ago
    I learned Z80 assembly in 1987, x86 assembly somewhere '91-92 can't exactly remember but it was in '94 when I met IBM Assembler (yes they called Assembler language which is also confusing) and I was like "what is this sorcery where assembly has an instruction to insert into a tree".
- deleted 6y ago
  [deleted]

by rst 6y ago

monocasa 6y ago

Embedded is going to become way less of a bestiary, at least in the five digit gate count RISC space. ARC, Xtensa, V850, arguably MIPS, etc. all worked in the "we're cheaper to license than ARM, and will let you modify the core more than ARM will" space. I'm not sure how they maintain that value add when compared to lower end RISC-V cores. I expect half of them to fold, and half of them to turn into consulting ships for RISC-V and fabless design in general.

projektfu 6y ago

Isn't z/Architecture just emulated on top of POWER? That's been my impression for a while.

monocasa 6y ago
They share RTL, but it's not just a POWER core with a z/Arch frontend.
dfox 6y ago
You probably mean "TIMI" which is the user-visible ISA of IBM's "midrange" systems (ie. AS/400 or System/i) which was from the start meant as virtual machine ISA that is then mostly AOT transpiled into whatever hardware ISA OS/400 or i5/OS runs on. z/Architecture (S/360, ESA/390, what have you...) is distinct from that and distinct from PowerPC. Modern POWER and z/Architecture CPUs and machines are somewhat similar when you look at the execution units and overall system design, but the ISA is completely different and even the performance profile of the mostly similar CPU is different (z/Architecture is "uber-CISC" with instructions like "calculate sha256 of this megabyte of memory").
- monocasa 6y ago
  No, they're probably talking about how modern z/Arch and POWER cores share a lot of HDL source these days.
  - projektfu 6y ago
    Yeah, I figured that most of the previously microcoded CISC instructions were basically software at this point.
    - monocasa 6y ago
      What's probably closest to the truth is that they have a very similar set of micro ops that they both translate to internally.
- chx 6y ago
  I learned Z80 assembly in 1987, x86 assembly somewhere '91-92 can't exactly remember but it was in '94 when I met IBM Assembler (yes they called Assembler language which is also confusing) and I was like "what is this sorcery where assembly has an instruction to insert into a tree".
deleted 6y ago
[deleted]