TVM Calculator Fun Part VI

A bit of fun messing around with time value of money (TVM) calculations on the HP-12c, RPN83P, DM42 and Plus42 calculators. The first HP TVM calculator was the HP-80, which used a very similar UI, where you could use the TVM solver within the calculator itself. The UI has been honed since then, and is used for solving other equations, and is also available for programs on the HP-42s.
Calculator Hardware:
HP12c: en.wikipedia.org/wiki/HP-12C
TI-83-plus: en.wikipedia.org/wiki/TI-83_s...
DM-42: www.swissmicros.com/product/dm42
Calculator Software:
Plus42: thomasokken.com/plus42/
RPN83P: github.com/bxparks/rpn83p
TVM-DM for DM42: forum.swissmicros.com/viewtop...
Puzzles:
2: www.hpmuseum.org/forum/thread...
3: people.eecs.berkeley.edu/~wka...
5: github.com/bxparks/rpn83p/blo...
6: github.com/thomasokken/plus42...
7: www.hpmuseum.org/forum/thread...