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From: Thomas Koenig <tkoenig@netcologne.de>
Newsgroups: comp.arch
Subject: Re: Why VAX Was the Ultimate CISC and Not RISC
Date: Mon, 3 Mar 2025 07:24:57 -0000 (UTC)
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Anton Ertl <anton@mips.complang.tuwien.ac.at> schrieb:
> John Levine <johnl@taugh.com> writes:
>>According to Anton Ertl <anton@mips.complang.tuwien.ac.at>:
>>>>That's not a fair comparison. VAX design started in 1975 and shipped in 1978.
>>>>The first ARM design started in 1983 with working silicon in 1985. It was a
>>>>decade later.
>>>
>>>The point is that ARM outperformed VAX without using caches.  DRAM
>>>with 800ns cycle time was available in 1971 (the Nova 800 used it).
>>>By 1977, when the VAX 11/780 was released, certainly faster DRAM was
>>>available.
>>
>>How was the code density?
>
> I have no data on that.  Interestingly, unlike the 68k, which was
> outcompeted by RISCs at around the same time, the VAX did not have an
> afterlife of hobbyists who produced Linux and Debian ports, so I
> cannot easily make a comparison.

The VAX is still supported with gcc and binutils, with newlib as
its C library, so building up a tool chain for assembly/disassembly
should be doable with a few (CPU) hours; you can then compare
sizes.