18 bit CPU; was: Speed now & then

Chuck Guzis cclist at sydex.com
Thu Apr 12 16:25:31 CDT 2018

On 04/12/2018 01:37 PM, Charles Anthony via cctalk wrote:

> And, if memory serves, the ":" was coded as a null character, causing it to
> disappear from the end of a line.

It depended on which character set you were using. The CDC 63-character
set didn't use 00, except as an EOL.  Colon was octal 63, which was a
percent sign in the 64 character set.  There were also CDC graphic and
ASCII graphic variants (print trains to match), so that, depending on
the print train, double quotation marks came out as "not equal" and vice
versa, along with other differences.   You learned to read your listings
both ways.

The "CDC Graphic" set seemed to be more suited to ALGOL programs, which
was a bit odd, since FORTRAN was the predominant HLL on those machines.
So, for example, the CDC Graphic set has all of the math relationals;
EQ, NE, GE, LE, LT GT, as well as the logical operators; OR AND NOT
EQUIV, as well as concatenation and up- and down- arrows.

This really wasn't any worse than IBM 6 bit character code.  Usually,
the question came up as "which one?"  IBM 1401 codes were not the same
as, for example, 7090 codes.

The good old days...


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