|here is a classic amongst casio calculators.
the 502p really offered some serious programming potential
plus the ability to save and load programs from cassette tape
- and play tunes!
it has 256 steps of merged keystroke, non-volatile program
memory distributed over 10 program slots, p0 thru' p9. 22
memories, labels, conditional branches, subroutines (4
levels), increment/decrement loops and indirect memory and
jump addressing and one of the first machines to offer a 10+2
display. ten levels of brackets were also more than most.
memory wise, everything was double the fx-501p, including program store,
registers and brackets. although the 501p was not released
earlier, it was positioned as a cut down version.
compared to the hp41c, a
competitor at the time, it was cheaper, could not be expanded
and had no alpha capability. on the plus side, it was cheaper
to acquire the fa-1 adapter for tape based storage than the
equivalent hp41c offering. it was also slimmer and more
to edit programs, you had a plastic overlay which showed
the row/column keycode. this you had to use to decipher the
program steps, until you learnt them by heart, that is.
another keyboard overlay was supplied with musical notes
printed. this was used to program the music feature.
basically, the music feature was a bonus derived from the
fact that the values in the program steps could be made to
play notes through the fa-1 interface.
the lack of alpha would be seen as a major drawback today,
but at the time, alpha capability was unheard of except on
the hp41c. other features missing now
more standard include, number bases, 2d stats (it has only 1d
stats) and memory partitioning. casio followed up this model
with the fx-602p which did have an
alpha numeric display, more memory and partitioning.
the machine came with a comprehensive program library
whose programs were originally derived from the fx-201p program library and later
turned into the fx-700p library. it
seemed that casio were fond of their programs, only adding
new ones to exploit the unique features of new models.
the unit is powered by 2 G13 button cells.
recently i found some cool stuff that i never knew the 502
could do, here,