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

[Dave Britten]

(03-14-2024 08:28 PM)bxparks Wrote:  That's fascinating. I took a quick scan through the TI-85 and 19bii manuals, now that I know what to look for, and I kinda like it. I'm going to think about how this feature can be implemented in RPN83P. No promises though. Quick question: Do these calculators exhibit the roundoff problems in unit conversions shown by Casio calculators?

They don't appear to. I just tried 1 ft^3->in^3 on one of my TI-85s (ROM 10.0) and I get an even 1728. I don't have my 19BII close at hand at the moment, but I tried on the HP Calc application on my 200LX (basically a 19BII), and also got 1728.


By the way, I don't think I've seen this mentioned yet, but if anybody wants to make RPN83P the primary operating environment on their 83/84, just install TI's Start-Up Customization app:

https://education.ti.com/en/software/det...tomization

It has a few different functions, but one of them is to launch an app immediately at power-on. Just set it to run the RPN83P app, and that's what you'll see whenever you power on. You can still drop back to the standard TI home screen with 2nd Quit like usual, and Start-Up Customization can be easily disabled by running it again if you ever want to revert to the original operation. Great way to get an RPN scientific from ebay for about $25!


Also I was thinking, rather than implement keystroke programming in RPN83P, how difficult would it be to launch a TI-Basic program from within the app? You could simply copy the stack to variables X/Ans, Y, Z, T, and L, and store the registers into a list (e.g. "REGS"), then bring the values back in after the TI-Basic program exits. No clue if the TI OS makes it possible to do this from within an assembly-language app.