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From: ForthNet@willett.pgh.pa.us (ForthNet articles from GEnie)
Newsgroups: comp.lang.forth
Subject: Memory Management/PIC
Message-ID: <2866.UUL1.3#5129@willett.pgh.pa.us>
Date: 9 Jun 91 18:06:53 GMT
Organization: (n.) to be organized.  But that's not important right now.
Lines: 30

Category 10,  Topic 36
Message 29        Sat Jun 08, 1991
B.RODRIGUEZ2 [Brad]          at 14:17 EDT
 
Hmmm... reading Robert Berkey's comments, I'm beginning to believe that _all_
existing Forth code will be rendered nonconforming by the BASIS.  Does anyone
have (nontrivial) counterexamples?

I must admit I rather like Ray Duncan's solution to the problem.  I hadn't
thought of using the exception trap to resolve this problem. This is good for
68K and LSI-11; does the 80196 have such a trap?

However, it's an oversimplification to state that only @ and ! are affected. 
I'm in the midst of converting a Super8 Forth from a RAM model to a register
model, and you wouldn't _believe_ how many words do memory reference. 
Granted, many of them access stack (trivial to keep aligned) or threads (via
IP).  Should the dictionary (threads) be kept aligned, and not data?  This has
implications for those who would write IMMEDIATE words to extend the compiler
(e.g., no 8-bit branch offsets).

- Brad
 Brad Rodriguez        | brad%candice@maccs.uucp      (God willing)
 B.RODRIGUEZ2 on GEnie | brad%candice@maccs.dcss.mcmaster.ca
 "Shoes for industry!" | bradford@maccs.dcss.mcmaster.ca  (archaic)

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