8/20/89

          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  (75126,3446)