Hi,
The discussion is not about a 3 pin regulator (78L05), that is a common part. It is about the 8-pin TE555-1 that people in this forum were confusing with a 555 timer. There are so many problems with the circuit shown when viewing as a 555, and the first clue, before even looking at the rest of the circuit was a 78L05 connected to a 555 in this way.... bogus. That, however is a common component used with some PIC processors, and that is the instant givaway that the chip shown is a PIC configured as a bipolar stepper motor controller, which is bogus as well, because it does not exist today, or perhaps never did.