How to identify integrated circuit (IC) functions from their Hewlett Packard (HP) number

On old HP boards all chips and boards all had an HP number to represent the name/number of the part. In many cases, the original part number was left out making it impossible to tell what the function was. Here is a list of HP part numbers and their real part numbers

=External Links=
 * http://users.frii.com/ralvarez/ebpix/01%20hp%20parts%20inventory.pdf
 * http://www.brouhaha.com/~eric/hpcalc/chips/

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