Extremely CISC instructions

[Tony Duell]

On Wed, Aug 25, 2021 at 7:33 PM Josh Dersch <derschjo at gmail.com> wrote:
>
> On Wed, Aug 25, 2021 at 11:19 AM Tony Duell via cctalk <cctalk at classiccmp.org> wrote:
>>
>> On Wed, Aug 25, 2021 at 7:07 PM ben via cctalk <cctalk at classiccmp.org> wrote:
>> >
>> > On 2021-08-25 11:08 a.m., Josh Dersch via cctalk wrote:
>> >
>> > > (The Three Rivers PERQ included a similar "RASTEROP" instruction in its
>>
>> Well, it might do.There is no requirement for the PERQ machine code
>> instruction set to include that, or any other particular instruction.
>
>
> Sure there is -- if it was left out, all of the user code that depended on it would stop functioning :).  I can remove instructions from the 11/780's microcode as well, but then it'd cease to be a VAX...

On the PERQ, different operating systems (POS, Accent, PNX) have
different microcodes and different machine code instruction sets.
There is no machine code that is 'PERQ'. So it would be quite possible
to produce an OS/microcode that dd not include rasterop instructions.

-tony