3 ms·

Thanks for your kind comments! Personally, I'd say that the IBM System/360 (1964) was the first widespread and influential 32-bit architecture. The Motorola 68

by kens 3y ago

Thanks for your kind comments! Personally, I'd say that the IBM System/360 (1964) was the first widespread and influential 32-bit architecture. The Motorola 68000 (1979) also deserves a mention for its use in the Macintosh. (And I'll argue with anyone who says it wasn't a real 32-bit processor :-) But, yes, the 386 started the 32-bit x86 architecture on most (non-phone) computers today.

peter_d_sherman 3y ago
Excellent points! System/360 is indeed interesting because (if my memory serves me) it was one of the first computational architectures to implement microcode (also, if I recall correctly, the necessity of updating of this microcode was one of the reasons that floppy drives were invented...) I'm also a fan of the Motorola 68000 -- I used to have an Amiga 1000 "back in the day". I'd choose it over any 8 or 16 bit CPU of the time period, but (correct me if I am wrong) it didn't have an MMU -- which would have made it a less-than-ideal candidate for writing a modern-day Unix compatible operating system, although the authors of AmigaOS managed to pull off quite an impressive multitasking OS on it, despite this fact, nonetheless... Also, as a 32-bit architecture (as opposed to discrete single-package IC CPU) we'd probably additionally want to remember the VAX 11/780 (1977) -- whose CPU was implemented as circuits of multiple simpler TTL IC's... (Oh sure, IBM might have done something like that earlier -- but the VAX 11/780 brought down the cost of IBM's comparable computing offerings by at least one order of magnitude! -- Although, even so, the 11/780 still would have been ridiculously expensive to the average person of that time period... (and yes, I know it was intended for mid-sized to large businesses, not people! :-)) But anyway, great article, and yes, the IBM System/360 and 68000 were indeed groundbreaking!
- snvzz 3y ago
  >it didn't have an MMU It didn't, but the real issue wasn't that it didn't have one. It was that it didn't support one. Specifically, the stack frame the 68000 pushes on bus error lacks the information to allow recovery (retrying). 68010 solved this. Many UNIX workstations are based on the 010, some use Motorola's MMU chip, most use custom designs.

by kens 3y ago

peter_d_sherman 3y ago

Excellent points! System/360 is indeed interesting because (if my memory serves me) it was one of the first computational architectures to implement microcode (also, if I recall correctly, the necessity of updating of this microcode was one of the reasons that floppy drives were invented...) I'm also a fan of the Motorola 68000 -- I used to have an Amiga 1000 "back in the day". I'd choose it over any 8 or 16 bit CPU of the time period, but (correct me if I am wrong) it didn't have an MMU -- which would have made it a less-than-ideal candidate for writing a modern-day Unix compatible operating system, although the authors of AmigaOS managed to pull off quite an impressive multitasking OS on it, despite this fact, nonetheless... Also, as a 32-bit architecture (as opposed to discrete single-package IC CPU) we'd probably additionally want to remember the VAX 11/780 (1977) -- whose CPU was implemented as circuits of multiple simpler TTL IC's... (Oh sure, IBM might have done something like that earlier -- but the VAX 11/780 brought down the cost of IBM's comparable computing offerings by at least one order of magnitude! -- Although, even so, the 11/780 still would have been ridiculously expensive to the average person of that time period... (and yes, I know it was intended for mid-sized to large businesses, not people! :-)) But anyway, great article, and yes, the IBM System/360 and 68000 were indeed groundbreaking!

snvzz 3y ago
>it didn't have an MMU It didn't, but the real issue wasn't that it didn't have one. It was that it didn't support one. Specifically, the stack frame the 68000 pushes on bus error lacks the information to allow recovery (retrying). 68010 solved this. Many UNIX workstations are based on the 010, some use Motorola's MMU chip, most use custom designs.