function that counts...

Albert van der Horst albert at spenarnc.xs4all.nl
Fri May 21 12:02:23 EDT 2010


In article <ht4406$92c$1 at reader1.panix.com>,
Grant Edwards  <invalid at invalid.invalid> wrote:
>
>Lest my allusions to Fortran IV be lost upon the less grizzled, only
>the first 6 characters were significant in Fortran IV identifiers, and
>removing all of the vowels from a longer word was an idiomatic way to
>create an identifier with a length <= 6.
>
>IIRC, the number 6 was originally chosen because that's how many 6-bit
>characters you could hold in a single 36-bit CPU register.  That way
>when writing a compiler/link/assembly you could compare two
>identifiers using a single "CMP" instruction.
>
>I'm not sure why 36-bits was such a popular ALU width, but many
>different vendors sold 36-bit machines back in the day.

16 bit mini computers were popular: the pdp11.
Now 3 FORTRAN char's fitted in one word (radix 40).
At least it helped to shoe horn identifier names into two words.

>
>--
>Grant Edwards               grant.b.edwards        Yow! Hand me a pair of
>                                  at               leather pants and a CASIO
>                              gmail.com            keyboard -- I'm living
>                                                   for today!


--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst




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