HP-65 STD PAC SD-01A Personal Investment weirdness

[Dave Britten]

The HP 80's TVM calculation functions were not at all idempotent either (they operate directly on stack registers as their inputs), so the operation of these 65 programs isn't hugely surprising.

For anybody else that wants to see it, the TVM program you mentioned can be found on Gene Wright's (old?) web site. This is typically the one I reach for if I need to do TVM on my 65.

https://www.rskey.org/gene/calcgene/ann65.htm

https://www.rskey.org/gene/calcgene/ann65i.htm