[TUHS] CRC calculation in the 1980s

Dan Cross crossd at gmail.com
Wed Sep 20 01:50:19 AEST 2023


On Tue, Sep 19, 2023 at 11:34 AM Paul Winalski <paul.winalski at gmail.com> wrote:
> For what it's worth, the VAX had a table-driven CRC instruction.  It
> wasn't very popular because on most VAX models it was actually slower
> than by-hand coding.  It is one of the instructions dropped from the
> microVAX instruction set used on all later VAXen, where it was
> emulated by the operating system.

I thought that was a general polynomial root finder instruction that
used Horner's Method?  Obviously it could be used in CRC calculations,
but I remember it being more general. I also remember reading about it
in the VAX architecture manual and thinking, "wow,
that's...something."

        - Dan C.


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