You have to get the current output pin state into a variable and then extract the bit required and use an IF on that. The current output pin states can be got by "PEEK $30,var" Using b0 or b1 is easiest as it gives access to the individual bits through the bitX variables.
To do something when output 2 is low ...
- PEEK $30,b0
- IF bit2 = 0 THEN DoIt
- PEEK $30,b1
- IF bit10 = 0 THEN DoIt
- PEEK $30,b2
- b2 = b2 & %00000100
- IF b2 = 0 THEN DoIt