All the reusability of a P-Switch block, and all the portability of a normal P-Switch! This shooter will generate P-Switches at its position, but only as long as another P-Switch of the same type doesn't already exist and a P-Switch of the same type isn't already active, so that you can only get a new one after the previous one has run out. Perfect for when you don't want to fill your puzzle level with reset doors.
Optimisations, shared routines, SA-1 and made it check for all slots and not just leave out the special two slot (in case you use P-switches from blocks, though it might have been done that way for this reason...).
The reason to use that is self-explaining: No need to use reset doors and pipes anymore if you want to get an unending amount of P-switches.