[jerf]

While I first fiddled with a Commodore 64, my first program that I could reasonably call non-trivial was on an HP-48G. Well, I'd call it trivial to me today, but it wasn't trivial to me then.

I can't speak to the TI series, but one nifty thing about RPN is that where 80s-style microcomputer BASIC tends to afford spaghetti code, the RPN afforded breaking your program down into functions. If you didn't break it down properly, your program turned into a series of hundreds of DUP DUP + SWAP3 DRAWLN 73 SWAP DUP - DRAWLN 0x838AFE7E8A9E 3 4 108 93 BLITPIX etc etc in an undifferentiated mass. (Those aren't the real opcodes, I've long since forgotten them and won't look them up, but that's sort of trying to compute where to draw two lines then dumping a pixmap to the screen.)