I also recall one of the magazines from the early days championing
computer-readable strips printed in the magazine, similar to a UPC code
but obviously much longer. Byte? Kilobaud? It's not coming up from
long-term archive....
There was a barcode reader 'wand' for the HP41 calculator, and later
tHP41 'solution books' (compilations of user-submitted programs came
with barcodes for all the programs in that book so you could scan them in
rather than typing them.
-tony