Live data from Hacker News

Intel 80386, a Revolutionary CPU

xtof.info

51–60 of 180 posts

Re: Intel 80386, a Revolutionary CPU

#51
post #40

Earlier quoted context omitted.

You're wrong about Microsoft here. They too have loads of experience developing their SW for multiple architectures, even moreso than Apple. Windows NT shipped on about 7 or so architectures including PowerPC for the Xbox360. And they also have experience with emulation, that's how they got Xbox 360 emulation on the newer X86 models. Just read their papers on arch emulation. What they don't have and Apple has is 10+…

The problem isn't even building NT for ARM/RISC-V/SH-4 or whatever, it's being able to reproduce enough of the surrounding universe that Windows on x86-64 has. Apple has more leverage over devs; they can say "No more x86-64 in N years" and the developers basically have to move to ARM or abandon MacOS. This bootstraps the market; people who want MacOS have to suck it in and buy ARM because it's the only new hardware w…

yeah, I wouldn't count microsoft or intel out.

arm cpu performance advantages at low power are great. i'm typing this on an m2.

but i'm sure intel will figure out how to have great cpu's at low power draws that perform well. amd already did. so i'm sure intel will.

Re: Intel 80386, a Revolutionary CPU

#52
post #8

They were in big trouble then. The entire company was riding on it being great. It could have easily gone awry as it did for Data General, Honeywell, CDC, AST, Tandy, Olivetti, Xerox, DEC Rainbow, AT&T Hobbit, Wang 2200 and Unisys. Strong survivorship bias on this one. Most of the once Titans are in or near the dustbin now, such as SDS, SDC and Fairchild. Intel's history was primarily as a memory manufacturer. They'r…

What’s their hope right now? Some sort of Quark-derived desktop CPU à la Dothan?

Imagine they got into making an ARM CPU competitive with Apple's? Or a server chip that is better than Ampera's, and sold at scale? I think they have the expertise and ability to do it.

Re: Intel 80386, a Revolutionary CPU

#53

They were in big trouble then. The entire company was riding on it being great. It could have easily gone awry as it did for Data General, Honeywell, CDC, AST, Tandy, Olivetti, Xerox, DEC Rainbow, AT&T Hobbit, Wang 2200 and Unisys. Strong survivorship bias on this one. Most of the once Titans are in or near the dustbin now, such as SDS, SDC and Fairchild. Intel's history was primarily as a memory manufacturer. They'r…

The DEC Rainbow would have been fine if they didn't do things like require special floppy disks that cost $5 each. DEC should have packaged the LSI-11 into a consumer machine. They had all the software, which was top shelf. I had an H-11, it was a great machine.

Thats an interesting alternative history thought experiment.

I wonder how early one could capture the complexity of the full PDP-11 microarchitecture on a single chip? Would it have been affordable? What about the support hardware?

Re: Intel 80386, a Revolutionary CPU

#54
post #53

Earlier quoted context omitted.

The DEC Rainbow would have been fine if they didn't do things like require special floppy disks that cost $5 each. DEC should have packaged the LSI-11 into a consumer machine. They had all the software, which was top shelf. I had an H-11, it was a great machine.

Thats an interesting alternative history thought experiment. I wonder how early one could capture the complexity of the full PDP-11 microarchitecture on a single chip? Would it have been affordable? What about the support hardware?

If Intel could do it, DEC could do it.

Re: Intel 80386, a Revolutionary CPU

#55
post #45

Earlier quoted context omitted.

Coming out with better chips at lower prices. I know how obvious that sounds but it's true. The difficulty is they need to make nearly decade-long bets that are the size of small countries economies due to the complexity of manufacturing and Intel's made a few bad ones recently. I don't know who to listen to on what chip design will be a market win in 2030 either. AI applications are extremely resource intensive so t…

Isn’t AI usually highly memory-bandwidth constrained? Designing a new powerful AI chip to rely on slow memory probably isn’t the best strategy.

I'd imagine when the AI dust clears there's going to be consumer and producer sides of AI and the consumer requirements will be a carveout of the producer.

This just appears to be the case with everything else. Making a video game, movie, song, computer program, etc, requires more resources than using one and there was a significant price delta between them for a long time.

Re: Intel 80386, a Revolutionary CPU

#56

The 80386 DX was a revolutionary CPU. It certainly foreshadowed the 486 and ultimately the Pentium. Most people I know only had a 80386 SX which was still revolutionary but it hid it well by being essentially a glorified (but slower) 80286 on the outside.

The 386SX could do everything the 386DX did, just slower. My first Linux box was a 386SX machine. Before Linux, I ran Coherent on it: https://en.wikipedia.org/wiki/Coherent_(operating_system)

Re: Intel 80386, a Revolutionary CPU

#57
post #53

Earlier quoted context omitted.

The DEC Rainbow would have been fine if they didn't do things like require special floppy disks that cost $5 each. DEC should have packaged the LSI-11 into a consumer machine. They had all the software, which was top shelf. I had an H-11, it was a great machine.

Thats an interesting alternative history thought experiment. I wonder how early one could capture the complexity of the full PDP-11 microarchitecture on a single chip? Would it have been affordable? What about the support hardware?

Hmm – the smallest, most highly-integrated PDP-11 (-compatible) package ever made was the QFP 1806VM2, with around ~135k transistors; it integrated MMU, UART, parallel interface, keyboard controller, etc, but did floating-point instructions in interpretive microcode.

I think that same transistor count was reached by Motorola on the 68020, which would've been around 1984, but would have needed the peripheral controllers mentioned here.

Re: Intel 80386, a Revolutionary CPU

#58
post #40

Earlier quoted context omitted.

You're wrong about Microsoft here. They too have loads of experience developing their SW for multiple architectures, even moreso than Apple. Windows NT shipped on about 7 or so architectures including PowerPC for the Xbox360. And they also have experience with emulation, that's how they got Xbox 360 emulation on the newer X86 models. Just read their papers on arch emulation. What they don't have and Apple has is 10+…

The problem isn't even building NT for ARM/RISC-V/SH-4 or whatever, it's being able to reproduce enough of the surrounding universe that Windows on x86-64 has. Apple has more leverage over devs; they can say "No more x86-64 in N years" and the developers basically have to move to ARM or abandon MacOS. This bootstraps the market; people who want MacOS have to suck it in and buy ARM because it's the only new hardware w…

> Apple has more leverage over devs; they can say "No more x86-64 in N years" and the developers basically have to move to ARM or abandon MacOS.

I think Microsoft could do the same thing as far as devs go. If Apple can exert that influence over devs with their extreme minority market share, I think MS could too. The problem for MS is their customers. Apple customers will buy whatever Apple puts out, because they're extremely loyal to the brand. The same isn't true for Microsoft, and I imagine that pressure would cause them to fold on any major changes.

Re: Intel 80386, a Revolutionary CPU

#59
post #8

Earlier quoted context omitted.

What’s their hope right now? Some sort of Quark-derived desktop CPU à la Dothan?

Imagine they got into making an ARM CPU competitive with Apple's? Or a server chip that is better than Ampera's, and sold at scale? I think they have the expertise and ability to do it.

A dual-mode ARM-x86 core would be an interesting CPU that they certainly have the skill to create. Thanks to the protected mode descriptor model, imagine having ARM64, ARM32, x86-32, and x86-64 code segments all coexisting in the same system, with no emulation nor virtualisation. There wouldn't be any overhead, because all instructions regardless of ISA get translated to uops anyway. They could add a RISC-V front-end too, just for completeness sake.

Re: Intel 80386, a Revolutionary CPU

#60
post #30
post #22

Earlier quoted context omitted.

Yes. For one no one has mentioned that the 386 itself had no on die hardware floating point. That seems like a huge one. Even if only a few instructions were added to the “core” some are huge like CMPXCHG, CMOV and although not an instruction itself the LOCK prefix. But the extensions are huge. We don’t even still use the floating point instructions of the 386/387 era. MMX was pretty lame but SSE and AVX are critical…

> although not an instruction itself the LOCK prefix. From what I can tell, the 386 had the LOCK prefix. Pin 26 (bottom left) is LOCK# driven by the LOCK prefix [1]. But CMPXCHG is very useful and wasn't available until 486, and Pentium added some other stuff that's important. [1] https://www.eeeguide.com/intel-80386-pin-diagram-description...

The 8086 had the LOCK prefix. Intel was thinking of multiprocessing from the beginning.
Post reply on HN