RPN83P: RPN calculator for TI-83+ TI-84+ inspired by HP-42S

[johnb]

(11-21-2023 08:50 PM)bxparks Wrote:  

(11-21-2023 07:38 PM)spiff72 Wrote:  I don't have an 83 or an 84, but I do have an 89 Titanium laying in a drawer. Is there any possibility that this could be ported to that platform? I think there was an RPN app of some kind for the non-Titanium version of the 89, but it doesn't work on the Titanium.

The TI-89, TI-89 Titanium, TI-92, TI-92+, and the TI Voyage 200 calculators use the Motorola 68000 processor, not the Z80. Basically nothing of the RPN83P code base would be reusable. The development tools of the 89/92/200 are completely different as far as I know, and I have not done any research on those tools. I don't know if TI ever published an SDK for those calculators, similar to their 83 Plus SDK. I know that those calculators can be programmed in C instead of assembly language, which would increase productivity.

Spiff, I succumbed to a post in a different thread and have my bidding engine set to try to grab a Ti-89 titanium for around $30-35. (I want one to as a non-HP comparison point for the accuracy of certain calculations in the HP-48s/g and 50g.) If I'm lucky and grab one cheaply, I might be able to be suckered, er, I mean convinced into collaborating on a port/rewrite attempt.

I've done a little research, and the following tools exist:

• Z80-to-68000 assembler translators
• Z80 assembler to C decompilers
• C/68000 compilers/decompilers
  

I haven't gotten as far as looking for Ti-89 development environments, but if it can be programmed in either C or assembler, we might have maybe 70% of our effort already done for us. The "workhorse" code @bxparks has written should be completely translatable; only the code that interfaces with the OS or the hardware would have to change. i.e. some of the code might be "recoupable" if not strictly "resuable."

Which brings me to a vaguely related question: "From the viewpoint of a user, not a feature implementor, what's the difference between the Ti-89 series and the 83/84 series?" If I don't snag a Ti-89, what would I miss -- if anything -- by grabbing an 84, for example?

[I already know what I'd gain: your (@bxparks) wonderful RPN environment ready to use! :-) ]