Hi,
Because the variable GPIO isn't defined....

This is because you're using PBC and it doesn't provide a way to directly write to the registers as you're trying to do - only PBP does that. As I wrote in my previous message you need to do as Darrel showed you earlier in the thread:
Code:
SYMBOL GPIO = $05     '$05 is derived from the memory map in the datasheet for 12F683
SYMBOL TRISIO = $85

Poke TRISIO, 0   'Set all available GPIO pins as outputs
Poke GPIO, 255  'All availble GPIO pins high.