CASIO fx-4000P scientific calculator from 1986

[Dave Britten]

I'd recommend getting ahold of an FC-200 (not the newer FC-200V) if you haven't already. It's an excellent financial calculator, and while it's lacking depreciation and bond calculations, I find it much nicer to program than the 12C, meaning you could implement those functions fairly easily, and still have room for more programs.

http://casio.ledudu.com/pockets.asp?type=98&lg=eng

Or you can just play with the TVM/amortization package I wrote for scientific models. This should work on any Casio with array memories (i.e. models with a "Defm" function, which is just about all of them up through the fx-9700GE and cfx-9800G).

http://dave.brittens.org/blog/casio-tvm-...ation.html