HP-42s Entering 4 complex numbers on the stack

[Vincent Weber]

The HP-15C is the only calculator in the world with a parallel imaginary stack, hence its edge in this matter.

Nonetheless I did these programs just for fun, in practice I find the 42S approach much more convenient even with this little drawback, you can see the complex number at one glance, be it in rectangular or in polar form!

And you seldom are in the situation where you know the exact 4 numbers to enter before hand. Usually you need to compute the complex numbers first. If the 2 parts have to be computed separately, then you need to switch to real mode on the 15C, hence breaking the nice "complex work exactly like real" paradigm. Oh well.

The 15C and the 42S are two excellent, legendary RPN machines. The 42S is much more capable in almost every way, save for little details like this one. The 15C is cuter, its design is unique, it has more prestige. I guess the 15C owner could see the 42S as a worthy successor, while keeping nostalgia for the 15C design...