Character width; was: these RTL or what?

7 Oct 2007

...

  6 bits was miserably crowded when numbers and
punctuation were added.  
 Six bits also is VERY inefficient for numeric data - all that stuff 
Curiously, the HP9100 _calculator_ used 6 bit words. This made sesne for 
user programs (and keycodes), but numbers were stored with one BCD digit, 
a sign bit and a blanking bit in each word (I think). The main processor 
register was 6 bits wide too.

The HP9810 that replaced it used 6 bit (logical width) memory, but I 
think only for the user programs (which again were lists of 6-bit 
keycodes). I think nunmbers were stoed in 16-bit-wide memory. Actually, 
since this machine had phyical memeory that was half the width of the 
logical memory (and circuitry to automaitcally do 2 memory cycles), this 
must be one of the few machines to have 3-bit-wide memory boards.

-tony

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Character width; was: these RTL or what?