23 Jun
2016
23 Jun
'16
10:08 a.m.
On Jun 23, 2016, at 12:11 PM, Paul Koning
<paulkoning at comcast.net> wrote:
Something to look into.... in the Electrologica machines (Dutch computers from the late
1950s to mid 1960s), double-length values are encoded with the sign bit replicated in each
word. I wonder if that makes this problem go away (entirely or mostly).
paul
On Jun 23, 2016, at 12:07 PM, Al Kossow <aek
at bitsavers.org> wrote:
...
I have also heard that 2s compliment was popular in shorter word length
machines because 1s compliment multiple precision arithmetic is a PITA
to implement.
That's true. It certainly can be done and has been. But since one's complement
arithmetic uses end around carry, when you have multiple word you have to defeat the word
carry and instead do the carry around the whole number.