After some work, I've discovered that the base-64 decode is based on the
following decode table:
char map[66] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"
",-\0";
The only change from the previously-published information is the graphic in
the next-to-last character position in the table, position 62. The earlier
documents stated this should be a plus sign; in fact it should be a
comma. It took reading 400 barcode symbols before I discovered the error
and determined the correction, so don't anyone feel they "blew it" -- it
doesn't happen often at all, and only when you are working with Code 128 or
the CatCue equivalent. When reading UPC, ISDN, and other numeric-only
barcodes this particular position isn't used (not enough one-bits density).
More information on cues can be found at
http://www.fluent-access.com/wtpapers/cuecat/index.html, and some
interesting tools for creating traditional-looking barcode presentations of
cues (as opposed to the stylized slanted-bar version that you find in the
Radio Shack catalog, Forbes magazine, and other places) can be found at
http://www.azalea.com/QTools/
Satch
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