On 11/18/2016 03:15 PM, Jon Elson wrote: > OH, yeah! Besides the limited instruction set, short registers only > half populated, etc., did you know that the 360/20 did not have an > adder? It could only increment/decrement. The data paths were only > 4 bits wide, so to add a 3 in register A to a 5 in register B, it > decremented A and incremented B until A went negative. It did this > for each nibble. I'm guessing a 16-bit add took over 100 us. I'd > ALMOST reject calling this a COMPUTER!
So not even as smart as a 1620 CADET, which did arithmetic via TLU? I guess I could believe that for register arithmetic, but did it do the same for memory-to-memory packed decimal operations? --Chuck
