Re: Experiencing Caldwell ... at CalStar

I used a hex editor to modify a ROM image of the Meade "Autostar II"
operating system. I located three instances of the string "Caldwell"
and changed them to my liking, but when loading my modified OS onto
the scope, the loader said "checksum error".

Now back at home, a few minutes research on the 'net revealed (thanks
to a fabulous gent named Dick Seymore):

       The checksum is a "simple sum" of the entire ROM file,
       -except- for the first 4096 bytes. Then the checksum is
       stored in "Intel-order" (least significant byte at lowest
       address) in the 4th through 7th byte in the ROM file.
       If that checksum is not correct, the Meade Updater will
       say that the file is corrupted.

Now it is a simple task to modify the OS any way I like, adjust the
checksum accordingly, then load the new OS onto the scope. When the
damn stupid Meade insists on referring to an object by its C
designation, the display will actually show:

  Wright 6
  Wright 14
  Wright 16 etc.

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