Re: AND and OR function pointers missing

From: Spiro Trikaliotis <ml-cbmhackers_at_trikaliotis.net>
Date: Fri, 14 Jun 2013 22:18:00 +0200
Message-ID: <20130614201800.GA18406@hermes.local.trikaliotis.net>
Hello,

* On Fri, Jun 14, 2013 at 09:41:30PM +0200 Ruud@Baltissen.org wrote:
 
> To be able to implement Basic 7 on a C64 and VIC-20 I need to have 
> the source code of these computers as well. Here I ran into a bit 
> of trouble. I found the pointers to the AND and OR function of the 
> C128 but I cannot those of the C64 and VIC-20. The code itself can 
> be found at $AFE6/$AFE9 and $CFE6/$CFE9. Of course I looked for 
> combinations of, for example, $AF and $E6 or $AF and $E5 but 
> nothing found.

Have a look at $A090/1 for $E8, $AF, and at $A093/4 for $E5, $AF. Note
that the byte before ($A08F and $A092) belong to it, it's some special
code belonging to AND and OR (for the hierarchy, IIRC?).

The whole table $A080-$A09D handles operators ("+", "-" (as infix), "*",
"/", "^", "AND", "OR", "-" (as prefix), "NOT" (prefix).

> I have started to look at the code itself how the BASIC codes are 
> found but haven't found out yet how the result is used. Having a 
> Commodore meeting in Maarssen again tomorrow, I have no time now 
> and I just hope that someone of you knows by chance and I haven't 
> to invent the wheel again.

You could have a look into "64 intern". ;)

Regarding the other mail: I am still looking into the sources, I will
send them to you ASAP.

Regards,
Spiro

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Received on 2013-06-14 21:00:12

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