x86 isn’t a VAX though, not all CISC architectures are equally complex (or RISC arch’s reduced), and VAX does have a reputation for being a particularly CISCy CISC. We don’t really know fully if the same tricks would have worked as well with it.

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PaulHoule 11 hours ago | parent | next [-]

What I've read was that DEC had a huge amount of regret over the PDP-11 having too small of an address space. It could be that experience led them to think the answer to their problems was to be early to market in the 64-bit age with the Alpha. They did have VMS for the Alpha and later Win NT but high-powered RISC processors were a crowded space in the 1990s.

	▲	panick21_ 3 hours ago \| parent [-]
		You can learn all about the details of how and why Alpha was developed: https://www.computerhistory.org/collections/catalog/10273826... Its in Part 2. If I remember correctly, it was basically 64bit because Alpha was basically a (good) virus inside of DEC. Or maybe like secret society that revolted against the leader of the company. Olson had killed 32 bit PRISM and they already had VAX that was 32 bit and people making processor for it. To get people all over DEC to buy into Alpha (Alpha barley had any budget of it own) it had to be something new, and winning 64 bit did make sense. Olson really killed basically everything that make sense, that DEC survived so long with Olson as CEO is kind of crazy. The amount of horrible decision starting as early as the early 70s is kind of crazy. VAX had also been early, driven by Gordon Bell not Olson, very few of the competitors had 32 bit processors then, and people like Data General and Prime struggled to develop them in response. Funny enough a hardware guy on the VAX team basically proposed RISC-like architecture but it was rejected because they optimized for code size. To bad that they didn't hit on the idea of compressed instructions.

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TMWNN 11 hours ago | parent | prev [-]

And, in fact, Mashey specifically discusses what you identified, and what Houle wrote (rushing to post a gotcha on HN, obviously without having read Mashey's lengthy writings).

	▲	kjs3 10 hours ago \| parent [-]
		Yeah, always good to read it. He goes into some detail about a hypothetical VAX-based x86 killer, tho some of it is "when I had beers with the guys designing the VAX..." reminiscing. Comp.arch was something really special. Guys like Mash, John McCalpin, Bob Colwell, Eugene Maya, Mitch Alsup, Terje Mathisen...folks who really, really understood computers, what the real tradeoffs are, did actual homework instead of guessing, and were generally able to discuss the issues without being jerks. Good times.