RPL for the 6502 circa 1981

[Egan Ford]

Reverse Polish Language:

http://www.portcommodore.com/dokuwiki/li...lmaual.pdf

Excerpt:

[walter b]

Quote:RPL, however, embodies a number of advantages over FORTH, among them ... a much friendlier user interface.

Gosh, on the background of RPL to RPN comparison, that must mean something for FORTH!

d:-/

[Garth Wilson]

Quote:For those who are interested, a discussion of the main differences between RPL and Forth is given in Appendix A.

I'm not familiar with RPL, but I can say that many of criticisms of Forth in the appendix are either invalid or outdated. For example, I never use a screen editor in Forth, but a full-featured programmer's text editor, and the turn-around time from writing a little piece of code to watching it work is instant; and my Forth assembler does not use "a bizarre, Reverse-Polish syntax for the actual assembly instructions" as the appendix says (nor does it have to do any parsing to do the regular order of mnemonic-operand. Its turnaround time to see something work is instant too).

[Katie Wasserman]

I think that you need to consider "RPL" in context. That context being the available languages on the Commodore PET with 8K of RAM circa 1980 when RPL was created. BASIC was built-in and slow but fairly memory efficient because it tokenized all the keywords. It also provided a built-in screen editor for those tokens/keywords. RPL used the BASIC-tokens and editor which was a huge plus since zero-RAM was needed for this aspect of the language. Programs written in RPL on a PET typically ran 10 times faster than those in BASIC while using less space. Admittedly, readability suffered because of the use of sometimes cryptic BASIC keywords but it is wasn't horrible to use.

The comparison to Forth is somewhat hyperbolic and totally unnecessary as there were no versions of Forth available for an 8K Commodore PET back in 1980-81. Although you might have been able to squeeze in part of some 6502 version of Forth there would be little memory left for use programs.

[Jim Horn]

Outdated, not incorrect - in 1981 most FORTHs were variants of figFORTH and were implimented as described. The language, like most, has come a long way since then.

[Nick_S]

Is this RPL for the 6502 in any way linked to the later HP RPL or do they just share the same name?

Nick

[Sylvain Cote]

They share the same acronym only.
RPL = Reverse Polish Language [this thread]
RPL = Reverse Polish Lisp [HP-28/48/49/50 series]
Sylvain

[Garth Wilson]

(12-17-2013 01:33 AM)Katie Wasserman Wrote:  I think that you need to consider "RPL" in context. That context being the available languages on the Commodore PET with 8K of RAM circa 1980 when RPL was created. [...] The comparison to Forth is somewhat hyperbolic and totally unnecessary as there were no versions of Forth available for an 8K Commodore PET back in 1980-81. Although you might have been able to squeeze in part of some 6502 version of Forth there would be little memory left for user programs.

I can accept that, as I'm thinking of the HP-41 Forth which used up nearly all the RAM and still it was a very poor, incomplete Forth.

One of the things in my long list of things to post on my website is my feature-rich 6502 Forth, and my 65816 Forth. Alas, it all takes so much time.

[Nick_S]

(12-17-2013 10:23 AM)Sylvain Cote Wrote:  They share the same acronym only.
RPL = Reverse Polish Language [this thread]
RPL = Reverse Polish Lisp [HP-28/48/49/50 series]
Sylvain

Thanks, that explains why I did not recognise much when I read through the document...

Nick