Hi,   
      
   I have a '83 breadbin C64 that glitches in one particular demo called "Parts"   
   (http://csdb.dk/release/?id=11689). It always happens during the first part of   
   the demo (intro text / vector buildings). Either short flashes of garbage   
   characters on the    
   screen, or sometimes the graphics completely mess up and the demo freezes,   
   accompanied by an abnormal sound.   
      
   The strange thing is, I have run 100s of different demos/games on this machine   
   and this is the ONLY one that doesn't work properly.   
      
   I've already ruled out the following:   
      
   -Disk/drive problems (tested with a known working drive, and another floppy)   
      
   -VSP problems (the VSP test shows no problems on this machine. Another C64 I   
   have DOES have VSP problems but it has no problems running this particular   
   demo).   
      
   -Faulty PSU (tested with another one, no change)   
      
   -Tested with another breadbin, same cables and equipment -> no glitch   
      
   -Both breadbins are PAL models   
      
   It's not a big issue since it only affects this one demo, but I'd still like   
   to solve this mystery. Maybe some tiny timing issue that only affects the most   
   sensitive programs? RAM, CIA, PLA, SID and VIC are socketed, and some of them   
   have had contact    
   problems in the past. But it's unlikely that would affect just ONE program.   
   And since some of the sockets are already pretty worn out, I'd prefer not to   
   put more stress on them unless needed.   
      
   It's unlikely a heat issue, since I have heat sinks on all the hotter chips,   
   plus a small fan. Whether or not I have the fan active makes no difference in   
   the glitches.   
      
   Any guesses to what could be causing a very specific problem like this?   
      
   Here is a video:   
      
   https://youtu.be/DsZaMRPYYWk   
      
   --- SoupGate-Win32 v1.05   
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