this model is the missing link between the older machines
like the fx-10, which had an incomplete function
set, to the more mainstream fx-29 and fx-39 style
it really is quite a nice little calculator, much smaller than you
would expect. it fits neatly in one hand. you can almost use it with the
same thumb. this palm-sized style reminds me of the hp 20
series, like the hp-25. when pocket sized
really meant it.
quaintly, it has the small zero digit of early casio machines like fx-10
and the memory 8r. like the older machines, this
one operates only in degrees and also hms->h is provided but not the
interestingly, natural log shares the same button as x^y. clearly
is implemented by continuation from ln by
a multiply and e^x. not a bad way to save a button assuming you wont be
testing y for integer.
improving on the fx-10 are trig inverses; arcsin, arccos and
memory (mc, mr, m+), change sign and, at last, proper exponential number
representation. ie. x*10^y. displayed as usual with a 2 digit exponent.
curiously, the exponent can only range to +/-39 inc. missing features are;
1/x, pi, and the antique a^n operation.
some thought has gone into the keyboard layout, the x^y and ln sharing
feature and the two = buttons, one is simple = and the other =M+. when
you're not using the memory, you can hit either button making quick