41–50 of 64 posts
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How were those processors made in a day-to-day basis? What did a typical Intel workspace look like back in the day?
I remember they had cubicles. Relatively glamorous compared to entirely open and echoey offices.
I'm always interested in all things (80)386 because this was basically the processor that launched the 32-bit computing revolution, at least as far as popular adoption of computers based on this processor go (there were earlier 32-bit processors -- but no earlier processor became as commercially popular (or as adopted by the mass population) as much as the (80)386). So this processor is of particular interest to me -…
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.
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!
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I remember they had cubicles. Relatively glamorous compared to entirely open and echoey offices.
What did the design process actually look like? Did they design at the gate level? Drawing manually or via software?
This is why managers shouldn't micromanage technical decisions.
Earlier quoted context omitted.
How were those processors made in a day-to-day basis? What did a typical Intel workspace look like back in the day?
I remember they had cubicles. Relatively glamorous compared to entirely open and echoey offices.
PS: Raise a paw if you remember the rainbow Apple logo on the triangle building along 280.
Author here. I've been looking at the 386 if anyone has questions. This post was inspired by userbinator's discussion on HN a couple of weeks ago about how many transistors there are in the 386.
Do you have more detailed information about what were the main issues with multiple OSes in Protected Mode? Was it implementation bug or fundamental architectural problems?
Do you know by any chance why did Intel miss POPF trap in Protected Mode?
https://devblogs.microsoft.com/oldnewthing/20160411-00/?p=93... https://docs.oracle.com/en/virtualization/virtualbox/6.0/adm... https://www.felixcloutier.com/x86/popf:popfd:popfq
Pentium Virtual Mode Extension (VME) and its Protected Mode Virtual Interrupts (PVI) solve performance burden of trapping, but despite being named _Protected Mode_ Virtual Interrupts this works only in V86 mode leaving Protected with this bug:
"The protected-mode virtual-interrupt feature — enabled by setting CR4.PVI — affects the CLI and STI instructions in the same manner as the virtual-8086 mode extensions. POPF, however, is not affected by CR4.PVI"
They even planned to patent PVI this in ~1992 https://patents.google.com/patent/GB2259794A/en and clearly knew about popf pitfalls back then.
Could this be what people in Computerworld article were complaining about? I dont understand how Intel not fixed it at all to this day.
Btw I find it funny and weird that Intel was lawyering around all the way in 1998 trying to suppress any knowledge of Virtual Mode Extension! Dr. Dobb's 'VME: Coming Out of the Cold' https://web.archive.org/web/20001217233100/http://www.rcolli...
Author here. I've been looking at the 386 if anyone has questions. This post was inspired by userbinator's discussion on HN a couple of weeks ago about how many transistors there are in the 386.
Great post. The most interesting thing to me was how historically significant the 386SL turned out to be. I had always mentally slotted it as a cheap cut-down part for the emerging laptop market, but it actually was a relatively sophisticated (3X the transistors!) precursor of the modern SoC.
What made 386SL special was introduction of System Management Mode (SMM). Intel sued AMD over Am386 SMM implementation, AMD tried claiming its not really SMM but jut some left over debugging ICE implementation :D https://ir.amd.com/sec-filings/content/0000898430-94-000804/...
Author here. I've been looking at the 386 if anyone has questions. This post was inspired by userbinator's discussion on HN a couple of weeks ago about how many transistors there are in the 386.
Total amateur here: does a 386 have “cleverness” or optimizations or does it just quite literally chug through a stream of instructions, adjusting registers and memory? I guess by this I am thinking about how newer processors do all kinds of stuff at the microcode level that mean you cannot anticipate precisely what instructions are being executed in what order.
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Love the post! Some DOI and Bitsavers links are broken (linking to righto.com or 404s). Also, where can I find "Automatic Place and Route Used on the 80386"? DDG only contains one result: this post.
There was some discussion of the automatic placement in this panel interview. If I remember correctly, the software that performed the placement was written by a graduate student who debugged it from a terminal at his dormitory. It was one of many project decisions on the i386 that management would have absolutely stopped had they been made aware. https://www.computerhistory.org/collections/catalog/10270201... "386 i…
you're asking somebody to answer RISC vs CISC in a subthread? there's not simple answer to that question, but the x86 family had a leg up with MSWindows compatibility and the processors they developed maintained that hegemony till they went astray with Itanium and were saved by amd64