65816 module (3)

From: Ruud Baltissen (Ruud.Baltissen_at_abp.nl)
Date: 2001-08-07 07:20:11

Hallo allemaal,

Just minutes before going to bed I remembered my 1999 65816 module which
litterally a hack of piggybacking one IC to the other. I put it in my C64,
put the 65816 of the module ontop of it, fired everything up, started
loading and ... worked fine :)
The only difference between the hack and the module is that it has 541, 245
and a 125 buffer in the address-, data-lines and R/W-line. And no 6526.
Why did I place buffers in the hack at that time? Because I was working on a
design where the 65816 could continue to do its work when not accessing the
C64. So the VIC only tristated the buffers.

It is nice to know that my module could work if I added those buffers but
with no explanation I'm not very willing to do that. What still puzzles me
is: why does the garbage only appear during loading??? If there is a
conflict with the VIC, why does the garbage not appear during normal
operation?
   ___
  / __|__
 / /  |_/     Groetjes, Ruud
 \ \__|_\
  \___|       http://Ruud.C64.org





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