Hi Ralph,
(Thank you others for quick responses, will reply after I have digested the messages and investigates the source pointers)
Understanding the current PVAccess (PVA) protocol may be a bit harder, but the documentation is better and the knowledge is certainly a lot more relevant than understanding the details of CA and how it came to be.
I saw that PVAccess is now present, but my understanding is that all of our internal beamline EPICS-services are running via CA protocols; so I think it will be some time before I can afford to ignore CA!
Nick