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

[bxparks]

(03-02-2024 06:10 PM)johnb Wrote:  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."

While your heart is in the right place, I think you are being overly optimistic. I would guess that almost nothing of RPN83P is transferable to the 89/92/200 calculators. The Z80 assembly code of RPN83P is tightly coupled to the TI83/84 OS, because the OS provides all of the low-level float routines, all of the keyboard scanning and button decoding, and all of the font rendering and printing to the LCD screen. I think it would be easier to rewrite the app in C, rather than trying to convert Z80 into 68000 assembly and emulating the 83/84 OS environment under the 89/92/200 OS environment.

I would be curious to be proven wrong, though, if someone tells me that it's trivial to set up dev environment, and create a "hello world" program for the TI-89/92/200.

(03-02-2024 06:10 PM)johnb Wrote:  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'm not sure what you are asking... The 89/92/200 calculators are clearly more powerful machines, for example, they have CAS capabilities, while the 83/84 calculators don't. But for 3rd party apps, the 83/84 machines are better documented and supported by the community as far as I can tell.

(03-02-2024 06:10 PM)johnb Wrote:  [I already know what I'd gain: your (@bxparks) wonderful RPN environment ready to use! :-) ]

I don't know if you are aware, someone on reddit told me that there is already an RPN program for the TI-89 that was created 20 years ago: https://www.reddit.com/r/calculators/com..._for_ti89/ . Apparently it runs only on the TI-89, not the 89-T, 92, 92+, or 200. I don't think the source code is available.

Anyway, my impression is that the developer community around the 89/92/200 collapsed around 10-15 years ago, most 3rd party compilers and tools are unmaintained and in disrepair, and much of the technical knowledge on creating 3rd party apps have been scattered and lost. Here's a good summary of the situation as of 2020: https://www.cemetech.net/forum/viewtopic...83&start=0

Personally, I'm more interested in the Casio 9750giii and cg50 series of calculators. These calculators are cheap, currently in production, and use relatively modern processors. The 3rd party development community seems active, and the compiler tools and libraries are readily available and maintained.