HP50g forums / community is there such alive?

[Vtile]

Thank you Gents, good tips and some gems at these posts. I find the article of the birth and reasoning behind RPL really interesting.

(11-03-2015 11:19 AM)Gjermund Skailand Wrote:  I suggest you look at

http://www.hpcalc.org/hp49/apps/editors/emacs211a.zip

Do a complete install with SDiag and extable on SD-card.
Then run AsnEmacs

Then you get an extended editor with description of USER-rpl (and all others commands as well) on the calculator.
I find it very helpful

Best regards
Gjermund

(11-03-2015 12:24 PM)Dwight Sturrock Wrote:  A useful resource is:

UserRPL stack commands
Posted by James M. Prange (Michigan) on 8 July 2007, 3:51 a.m.

This article is located on this forum.

As with any programming environment, you don't have to know all the features for it to be useful. The unlimited stack with 7 or so levels visible makes it worthwhile learning the basics of this machine.

(11-03-2015 01:40 PM)peacecalc Wrote:  Hello Vtile,

I don't know where your problem exactly is:

Quote: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.

The question "Why" can only answered by developers of the family 48/49/50. They intended that programming language and found it useful for "future user" (meant in the times of the beginning of the product family).

From LISP comes the abilities for working with lists and from RPN you get the abilities working with a stack. But some structure are not as consequent as expected:

For instance the IF THEN ELSE END construct:

<< 1, IF THEN 2, ELSE 3, END >> will result 2, after evaluation same result when you use << IF 1, THEN 2, ELSE 3, END >>

That is dued to rules for high level languages. The IF works like a function so the boolean (happy birthday 200 years yesterday) evaluation can be done afterwards IF or before (like RPN).

And at last a little tip:

For bigger programming projects avoid using stack-commands, the programs are very hard to understand some times later (or for other persons).

And of course there are actually less questions (and answers) about the hp 50g,
because that machine exist some years. But the people who are new with that machine have to do some hard work nearly 1600 pages of handbooks. And an enormous treasure of knowledge of experienced user. It is a treasure you have to search for some places same as a lot of users and I do: hpmuseum, hpcalc, comp.sys.hp48 and last not least: hp own's site mobiles and handhelds concerning

greetings
peaceglue

Indeed and 30 years of cumulated knowledge (=the experienced users) to take found out.

(11-03-2015 03:20 PM)Didier Lachieze Wrote:  

(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.

I recommend the reading of:

• "RPL: A Mathematical Control Language", by W. C. Wickes, published in "Programming Environments", Institute for Applied Forth Research, Inc., 1988
• and RPLMan.doc
  

The problem with 48 documentation is that 48 is not compatible to 50 at all aspects or is it? RPL Programming Guide from Goodies Disk 4. is a gem, discrace that HP didn't update it when they did launch 49 and 50 calculators, that is one documentation that should be in HPs own download section. *mad*