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Free42 with big stack, test version
02-05-2021, 11:05 PM (This post was last modified: 02-06-2021 12:05 AM by Peet.)
Post: #50
RE: Free42 with big stack, test version
(02-05-2021 09:45 PM)Thomas Okken Wrote:  When you turn on the big stack, you get big stack behavior. That is different from four-level stack behavior. That's the whole point. The only way to be perfectly consistent with the four-level stack is to have a four-level stack, which is why that mode is still there.

I ment something else. If you have 4 or more Levels on the big stack, change mode to the 4 level stack, do an aritmetic and change back to the big stack, than the 4: and 3: level now have the value from the former 3: level because of the behavior of the T-Register in 4 level mode. That may be technically correct but still strange because you don't see the changing of the content. That's why I liked your decision to remove 4STK and NSTK from MODES and put it to the preferece setting.

(02-05-2021 09:45 PM)Thomas Okken Wrote:  Since the X register cannot be empty with the four-level stack, obviously you can never get an error message with CLX, there is always a number there to replace with zero.

The Prime didn't have a four-level stack and produces no CLX-Error. Even well known Programs like Notepad or Word did not produces errors with backspace in an empty document. That was an annoying error-message on some (not every) RPL calculators and I don't understand why you choose this for the Free42.

(02-05-2021 09:45 PM)Thomas Okken Wrote:  Are you having difficulty grasping the equivalence between "level 1" and "X register", and "level 2" and "Y register"?

No, no difficulties but it looks a bit sloppy, even HP never uses X<>Y on Calculators with an dynamic stack. It was SWAP on RPL or arrows on the Prime but X and Y are used for math equations and not for the stack on this calculators.

(02-05-2021 09:45 PM)Thomas Okken Wrote:  Which question would that be? I must not be paying attention?

There is no example from HP Calculators in for a T -od L-Register on a dynamic stack. If you do so, your setting new standards and I asked if there is a strict logic behind or whether they result from the programming.
Is there an equivalent to the T-Register? Is there a LastX in a numbered stack? If yes, does it behave like LastX on the 4 Level Stack?

(02-05-2021 09:45 PM)Thomas Okken Wrote:  What are you even talking about?

In RPL the dynamic Stack was implemetet as part of the system and consistent. On the Prime a bit adapted for RPN but not particularly elegant. On the Free42 I thougt it was on development and I wantet to point out possible discrepancies so you can take this into account if necessary or ignore them if you want.

My calculators - former: CBM PR100, HP41CV, HP11C, HP28S - current: HP48G, HP35S, Prime, DM41X, DM42
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RE: Free42 with big stack, test version - Peet - 02-05-2021 11:05 PM

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