Re: Two new PRGs

rbaltiss_at_worldaccess.nl
Date: 1998-01-31 20:48:48

Hall Steve,

> I don't know if this is the answer, but the C64 BASIC interpreter uses a
> > address table that contains routine addresses subtracted by one.  It
> > pushes these addresses on the stack and uses RTS to jump to them.  (RTS
> > increments the return address by one.)  Could it be that your disassembler
> > doesn't see the routine because of this?
> 
I already found that out due to other 'unexamined areas'. There is also a list 
which is used with indirect jumps.

> ............  Although this routine does not appear to be referenced
> anywhere in BASIC, the vector at locations 3-4 points to its address.
> Presumably it is provided for the benefit of the user who wishes to
> pass parameters in a USR call, or the like."
> 
> So there ya go!

Thanks.

I used the binaries provided by Marko to make a complete disassembly within 30 
minutes. Within another hour I replaced almost all my own labels by the 
original by the original ones. The only things which are missing is the comment.

Hallo Marko,

I downloaded the binaries of the PET donated by Olaf Seibert. But I found out 
there must be something wrong with it. The first thing I noticed was that the 
sizes were wrong. I know that two extra bytes probably mean that the start 
address is added by a commodore but here we are talking about 5 or more bytes 
extra. Please have at least a look.

Groetjes, Ruud

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