Sujet : Re: is Vax addressing sane today
De : ldo (at) *nospam* nz.invalid (Lawrence D'Oliveiro)
Groupes : comp.archDate : 08. Sep 2024, 22:09:39
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vbl3qj$22a2q$1@dont-email.me>
References : 1 2 3 4 5 6
User-Agent : Pan/0.160 (Toresk; )
On Sun, 8 Sep 2024 17:56:55 +0000, MitchAlsup1 wrote:
The problem with VAX was NOT that one could not put a lot of work in a
single instruction;
no,
The problem with VAX is that it made putting too much work in a single
instruction easy.
Perhaps there is also the issue of the wildly-variable instruction length.
A single VAX operand descriptor could be up to 6 bytes; I think the
instruction with the most general-format operands could have 6 of them:
so, plus opcode, such an instruction could be 37 bytes long.
While the shortest instruction could be just 1 byte.
Even those who are talking about “post-RISC” are, I think, still in favour
of RISC-style fixed instruction lengths.
…