Mark, Dude! I've never seen those before.

WOW! The possibilities ....

A quick FIND command in DOS reveals the following chips have it.

18F2221, 18F2321, 18F2410, 18F2420, 18F2423, 18F2450, 18F2455, 18F2458, 18F24J11, 18F24J50, 18F2510, 18F2515, 18F2520, 18F2523, 18F2525, 18F2550, 18F2553, 18F25J11, 18F25J50, 18F2610, 18F2620, 18F26J11, 18F26J50, 18F4221, 18F4321, 18F4410, 18F4420, 18F4423, 18F4450, 18F4455, 18F4458, 18F44J11, 18F44J50, 18F4510, 18F4515, 18F4520, 18F4523, 18F4525, 18F4550, 18F4553, 18F45J11, 18F45J50, 18F4610, 18F4620, 18F46J11, 18F46J50, 18F65J50, 18F66J11, 18F66J16, 18F66J50, 18F66J55, 18F66J60, 18F66J65, 18F67J11, 18F67J50, 18F67J60, 18F85J50, 18F86J11, 18F86J16, 18F86J50, 18F86J55, 18F86J60, 18F86J65, 18F87J11, 18F87J50, 18F87J60, 18F96J60, 18F96J65, 18F97J60

I didn't cross-reference with PBP compatability.

Now then ....

What to do with them ???