You want to buy an Athlon but you don't know whether the retailer is trying to offload an old Athlon manufactured using 0.25 micron technology? From the outside, the old 0.25 devices (model 1) and the 0.18 devices (model 2) look identical. You also don't know which voltage is needed for the device and this can vary between 1.6V and 1.8V according to the clocking frequency.

With the help of the following table you can read the labeling on the top of the Athlon processor to find out.

This figure shows the label again enlarged. The top line is the most important one, the so-called Ordering Part Number (OPN). The lower line is the serial number which is not so important for you. The following table explains the individual lettering and numbers used.