What information is encoded in the serial number?
The week it was manufactured. A serial number is of the form: SGywwnnnnn Where y is the last digit of the year of manufacture, ww is the week of manufacture, and nnnnn is the individual serial number. Thus SG45101234 is the 1234th unit manufactured in the 51st week of 1994. The “SG” is the country of origin (apparently all are manufactured in Singapore). It seems a similar scheme is used for many HP calculators.
