7 Feb
2022
7 Feb
'22
11:51 p.m.
The PDP-10 is interesting (or strange) in that it uses
skips to convey
the result of various tests and comparisons.� You don't use tests to set
PC flags and do conditional jumps on them (like nearly every other
architecture that comes to mind immediately).
It's worth pointing out that the PDP-10 _does_ have PC flags and instructions to
test them (just check my domain name!) but they're not used for things like
zero/negative tests. There is a carry flag of sorts (the APR overflow bit) but it was
almost never used. With 36 bits you didn't worry much about overflows :)
Bob