>Can anyone please tell me where the description >on how to use SVC's in z/OS is.
No such description is really needed. You do not use SVC's. You use services. A service may choose to use an SVC as its method of getting control (just as it may use a PC or a BALR or a BASSM). If you were intending to write your own SVC routine that might be a different matter, and you would be strongly discouraged from doing so. If you were asking something like "I see an SVC issuance in a trace, what service was it?", then the diagnosis reference mentioned by Ray Overby can help. Peter Relson z/OS Core Technology Design
