FORTH for the SHARP PC-E500 (S)

[Klaus Overhage]

I am able to read and understand assembly language. I have already written smaller assembly routines and can certainly learn a lot from you. At the moment, however, I would first like to report on my experiences from the point of view of a Forth500 user.

Your implementation of toupper and tolower shown above does not work for me. It throws exception # -13: undefined word with toupper as the first entry in the dictionary. The old implementation with the addition of DUP and SWAP works:

Code:

: toupper   ( char -- char ) DUP [CHAR] a [CHAR] { WITHIN IF $20 - THEN ;
: tolower   ( char -- char ) DUP [CHAR] A [CHAR] [ WITHIN IF $20 + THEN ;
: strupper  ( string len -- ) 0 ?DO DUP I + DUP C@ toupper SWAP C! LOOP DROP ;
: strlower  ( string len -- ) 0 ?DO DUP I + DUP C@ tolower SWAP C! LOOP DROP ;

I was also able to run the RC4 cipher program from the wikipedia entry for Forth without any problems.
(see https://en.wikipedia.org/wiki/Forth_(pro..._language)

When using WORDS, it happened to me that a BREAK via the ON key crashed the computer. I think that's what happens when the ON button bounces. And there is always an exception #-28 for "user interrupt", which is not so nice. Is it possible to use another key especially for WORDS, for example C-CE, for normal exit without exception? That would help a lot if you just want to look at the new words.