non-binary hardware (was: Absolute size of 'short')
News system
news at ism780c.isc.com
Wed Sep 14 06:43:35 AEST 1988
In article <6266 at venera.isi.edu> lmiller at venera.isi.edu.UUCP (Larry Miller) writes:
>>By the way, does anyone know of a non-mechanical digital calculator or
>>computer that isn't essentially binary?
>
> There was also the IBM 1620, a BCD machine. Yes, decimal, but
> all arithmetic was performed using table lookup, floating point
^^^
> in software, so I guess it could be called a nonbinary machine.
>
>Larry Miller lmiller at venera.isi.edu (no uucp)
Well, actually not quite all arithmetic was by table lookup. Program counter
incrementing was done with traditional bcd (i.e. binary) add logic. So I
would call even this machine binary.
BTW: There actually was hardware floating point. The harware supported
floating precision of from 2 decimal digits to an upper bound on precision
limited only by the amount of memory available to hold the data.
Marv Rubinstein
More information about the Comp.lang.c
mailing list