OT - cynical speculation

/me wonders if all the PIC chips are internally the same, and are
specialised to a particular model (16f88, 18f252 etc) by a combination
of voltages applied to certain pins, which burns a combination of fuses,
when they come off the production line.

I'm well acquainted with a similar practice having been used at board
level by a large minicomputer manufacturer I worked for in the 1980s -
client companies paying thousands of dollars for a 'motherboard
upgrade', engineer comes in and changes a jumper, enabling twice the
memory and double the cpu speed.

-- 
Cheers
David