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Comment by theodorethomas

1 day ago

The 486 and https://www.delorie.com/djgpp/history.html changed everything.

Suddenly, it was possible to imagine running advanced software on a PC, and not have to spend 25,000 USD on a workstation.

It's hard to convey to today's generation, who think Ivy Bridge to Haswell was a big jump or whatever, how awesome the 286 -> 386 -> 486 changes were to personal computing. It felt almost like what going from a NES to a Super Nintendo to a N64 felt like. The improvements were astounding.

I remember trying to run a game, Rise of the Triad, which was built with an improved Wolfenstein engine iirc, and having it struggle on my 386 unless I made the viewport as small as possible. At which point it told me to buy a 486... well I did eventually, I guess it worked.

  • Had the same experience with Doom II. Got it to run surprisingly well on a brand new Tandy 486DX2 + 4MB RAM, though I seem to recall having issues with SoundBlaster compatibility.

It was really the 386 that was the beginning of modern computing, since it had a mmu.

  • Several operating systems on 286 (eg Xenix, Coherent, OS/2) used its MMU for multitasking and memory protection. See https://en.wikipedia.org/wiki/Intel_80286#Protected_mode

  • Except the 486 had hardware floating point, essential for technical work.

    • An MMU is pretty much necessary for robust multitasking. Without it, you are at the whim of how well software behaves. Without it, it is more difficult for developers to create well behaved software. That also assumes good intentions from programmers, since an MMU is necessary for memory protection (thus security).

      While emulating an FPU results in a huge performance penalty, it is only required in certain domains. In the world of IBM PCs, it was also possible to upgrade your system with an FPU after the fact. I don't recall seeing this option for IBM compatibles. While I have seen socketed MMUs on other systems, I don't know whether they were intended as upgrade options.

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    • That's an advancement but that's a matter of speed an simplicity. An MMU is a huge before and after, it's still the biggest separator of CPUs today. The most important detail to understand a CPU is whether it has an MMU.