Re: Why VAX Was the Ultimate CISC and Not RISC

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.