AMD's Thunderbird
did indeed only officially appear in June of this year. However, the chip
or its Socket-A packaging may have actually been produced in late 1999.
Athlon chip markings consist of both a part number and a serial number
directly beneath it. Here is an example from a Slot-A Athlon:
The year in which the processor was produced is indicated by the third
and fourth digits in the serial number ('00' in the example, representing
2000). The week in the year it was produced is shown by the next two
digits (here '13', the last week of March).
To decipher the part number and make sure you actually got the chip you
paid for, see the following examples from AMD's technical
documents.
For Socket-A Thunderbirds:
And for Slot-A Athlons:
