• Got a 1200XL with bad video? With a few simple changes under the hood, you can get rid of that tearing, fuzzy screen and add separate CHROMA operation.

  • Unlike the movies, the sequel to the CLRPIC modification is much "better" than the original. If you were disappointed that the CLRPIC mod did not allow for a COMPOSITE output, or felt intimidated by the lengthy list of changes in the original upgrade, then you are at the right place. This version only requires you to remove 10 components and add 4 wires and 4 components! IT IS STILL A GOOD IDEA TO HAVE SOME ELECTRONICS SOLDERING SKILLS. Also, these changes were developed empirically, which means I just diddled with the values until they worked. The output is very good - better than an 800XL and, depending on your preference for overdriven characters, better than a 130XE or 800 in separate CHROMA or COMPOSITE video.

  • On with the changes. As in the original CLRPIC article, I will list the existing component in the left column and what to put in it's place in the right column. A "--" indicates that nothing is to be connected and "wire" calls for a jumper, shorting out the part.
    REMOVE:                  REPLACE WITH:
    C115      10uf                wire
    C60       100pf               --
    R187      1meg                2.2K
    L15       820uh               wire
    R188      750                 680
    CR19      1N4148              --
    C119      3.9pf               --
    C62       10pf                wire
    R24       180                 47
    R23       180                 47
  • Add a wire from R44 (either side) to pin 5 of J2.

  • That's all!! Works fine on a number of monitors that I have. Now, get to it, Puff!

    Bob Woolley (

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