Hi,
.... I thought Rev-Ed preferred to not give away the info on which PIC chip it was originally.
Not really any secrets, see
HERE in the "Manuals" section of the forum for the "Advanced Technical Details". It also says:
"The M2 series chips are engraved with the full PICAXE name**, whilst other parts are simply marked with the base Microchip 'PIC' name. See the table below for the names engraved on the current PICAXE parts.
** M2 surface mount parts (and in times of supply shortages, DIP parts) may also be supplied marked with just the standard base Microchip 'PIC' name."
AFAIK, the "Labels" are Laser-Etched onto the packages in the Microchip factory, which presumably is only worthwhile for large volume products. Smaller volume products (e.g. X2s and SMD) and in times of short supplies (as of microchips in general, Globally at the moment) can be programmed by Rev Ed themselves onto "blank" devices, which would carry the base Microchip part number.
Cheers, Alan.