HP calculator with largest math (stats, logic, etc..) and data structure functions

[grsbanks]

(09-24-2018 11:48 AM)JSBach Wrote:  The HP-15 had 2 parallel stacks, one for the real parts and one for the imaginary parts.
The HP-42 had something better: Every stack member could be a real or a complex number.

Very true, but entry of a complex number from its real and imaginary constituent parts uses two stack levels. What was in T when you enter a complex number is lost. This doesn't happen with the 15C.