Free42 NSTK ENTER behavior

[squid2]

(10-16-2021 03:32 PM)Peet Wrote:  

(10-16-2021 01:07 PM)squid2 Wrote:  I think the reason I feel this way (compared to old timers like Peet) is that I haven’t been using classic HP 4-register “stack” based calculators for 40+ years. HP switched to an “unlimited depth” (normal to me) stack in RPL machines years before I was born, and I was taught RPN as being based on a stack rather than four registers.

Wow, not only an other argumentum ad hominem, also fictitious facts. Not exactly a basis for factual discussions.

FYI: The first HP Calculator with "entry RPN" (big stack) was the HP-28c (1987). In the current Line-up HP has 4 RPN Calculators. 3 with "classic" and only one with "entry" RPN.

Sorry, this wasn’t meant to be an attack on you, just explaining my perspective on what I’m used to and what feels intuitive to me. Someone who has been using 4-level RPN for a long time would find the behaviour to be what they expect. I’ve been used to big stacks, and that’s what I learned RPN as.

My point was just that as someone who was taught RPN as something operating on a stack (that can be arbitrarily large) rather than 4STK, the behaviour of NSTK mode is much more intuitive. The original concept of RPN was also based on an arbitrarily deep (and variable depth) stack; the 3 or 4 register “stacks” were done due to hardware limitations of the 60s/70s. It’s easier to work with NSTK since you don’t need to keep track of stack depth and worry about overflowing it (as long as you aren’t being deliberately wasteful). Furthermore, with a big stack, programs and subroutines can freely use the stack without worrying about clobbering the caller’s stack.

I said HP switched to big stack entry RPN in RPL machines before I was born (I was born after 1987). Yes, they haven’t discontinued the 12C which predates 1987, and the 35S is a relatively recent model that still uses 4-level RPN to remain familiar to people used to old calculators, but neither of those are RPL machines.