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HP50g forums / community is there such alive?
11-03-2015, 03:31 PM (This post was last modified: 11-03-2015 03:34 PM by Bill Platt.)
Post: #18
RE: HP50g forums / community is there such alive?
(11-03-2015 11:10 AM)Vtile Wrote:  Why is that RPL (Reverse Polish Lisp) is not RPN (Reverse Polish Notation = arguments before commands) programming, in sense that arguments are given before commands and there is atleast two accumulators where the "data" is "loaded" before execution.

You need to RTFM41.

RPN does not equal RPL. Similar in some respects; completely different in others. Even the stacks aren't the same! 4 ENTER 2 ENTER + returns 4 on RPN, and 6 on RPL...RPL has numbered stack levels and a command line which is not level 1. ENTER in RPL functions contextually either as ENTER or DUPlicate. All RPN machines have a special programming logical space. This is not true in RPL as RPL has multiple object types on the stack including programs. Looping in RPL is GTO and GSB and Flags and all that jazz. Which is again in special programming space. RPL is IF-THen, For, Repeat, Do, etc (like pascal...sort of). All programs in RPL are saved as objects no different than any variable. Variables are named and declared. RPL has extensive stack manipulation tools and commands and you can build programs that sort of act like RPN but really why would you torture yourself that way other than for simple things? You have a real language.
If you love RPN programing, just load Hrastprogrammer's emulator, or Christoph Giesselink's emulator, onto your 50 and run a 41CX virtually.

You need to read and slow down. And the hint above is important: you need to read mostly HP48 (and HP49) period stuff because that is what RPL is and ran as for over 15 years. The 50G is new hardware that is all.

PS RPL handles Algebraic don't have to turn all equations into Reverse is more different than similar, once you dig past the superficial similarities. (Basically RPL is the most powerful broadly useful interface for a high powered handheld, ever.)
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RE: HP50g forums / community is there such alive? - Bill Platt - 11-03-2015 03:31 PM

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