Hi Michael,

The PIC12C508A doesn't have a PORTB so your WPUB statement will obviously create an error.
As mark_s has already stated, setting option register bit 6 to 0 will enable weak pull ups on GP0, GP1 and GP3
These pins must be set as inputs.

Note, hard pull-ups can always be implemented instead of weak pull-ups.

I trust this helps.

Cheers
Barry
VK2XBP