CYBER word length

[Karl Heuer]

In article <612 at astroatc.UUCP> philm at astroatc.UUCP (Phil Mason) writes:
>The Cyber word length was selected to be 60 bits because of the number of 
>exact divisors it has : 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30.

I thought it was an arbitrary decision based on some piece of hardware they
had to interface to.  (Hearsay.)

>CDC thought that nobody would ever use more than 64 different symbols for
>I/O so they made their "byte" six bits long.

Actually, I believe they used "byte" to denote a 12-bit quantity, so one byte
normally contains two characters.

>Packing ten of them in a word is convenient, to say the least.

Yeah.  I liked being able to store strings in integers instead of arrays!
(This was before FORTRAN had a character type.)

Karl W. Z. Heuer (ima!haddock!karl or karl at haddock.isc.com), The Walking Lint