🚀 go-pugleaf

In article <662aej$7...@tooting.netapp.com>, Guy Harris <g...@netapp.com> wrote:
>Tom Perrine <t...@galt.sdsc.edu> wrote:
>>Hmmm, another clone was born at GE a bit later, I know that the GE600
>>series was a an IBM 7090 with the opcode and address fields swapped
>
>...and a significantly different instruction set (e.g., I don't *think*
>the 709x had as many addressing modes as the GE6xx).

No where near as many.  On the other hand, the product spec for the 6x5
actually did say something close to "it should feel familiar to a
programmer experienced with the 7090."  This isn't folklore, I actually
saw the GE specs, although it was a long time ago.

>I vaguely remember somebody, perhaps here, saying why the GE6xx had an
>instruction to convert Gray code to binary; anybody know why?

Because it was also had a military version: the A605 (airborne) M605 (truck
ship born).  Gray code is used to encode the position of rotating shafts
(like old style radar antennas) because it has the nice property that only
one bit changes at each transition.

A cute generation in hardware design.  The M605 had discrete component
boards (this was 1965), but _every_ transistor was in its own little
shock absorbing socket.

-- 
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Sarr Blumson                    sa...@umich.edu
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