For my own morbid curiosity, and because it came up on another mailing list I'm on [1], what machines commercially avaialble were sign magnitude and one's complement? Every machine I've encountered was two's complement (okay, IEEE 754 [2] is a sign magnitude format but I'm talking about integer implementations here, not floating point). I've only found reference to one sign magnitude computer (the IBM 7090, release in 1959) and a few one's complement machines (mostly the PDP series from DEC).
Where there others? And honestly, are there any machines that use anything other than two's complement today? -spc [1] http://lua-users.org/lists/lua-l/2015-08/msg00386.html [2] AKA floating point.
