Re: [stella] Weird Donkey Kong disassembly prob

Subject: Re: [stella] Weird Donkey Kong disassembly prob
From: Thomas Jentzsch <tjentzsch@xxxxxx>
Date: Fri, 2 Apr 2004 20:28:55 +0200
Paul Slocum wrote:
> So I did a file diff on the original Donkey Kong ROM and the one produced
> from the disassembly.  I found 6 differences in the file, and all were
> because the original game reads from input ports using $30 as the base
> input address and vcs.h puts the base at $00.  I changed vcs.h to use the
> base address $30, and then the game worked fine on a real 2600.  I have no
> idea why.

This was the line causing the problem:
  asl CXP1FB ; check if the obstacle was hit by the hammer

If the base is at $00 this writes to RSYNC!

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

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