Format of SK-UPPS Protocol Control Block (PCB):
Offset	Size	Description	)
 00h	WORD	(big-endian) protocol type
 02h	WORD	protocol mode (see #03850)
 04h	DWORD	-> Receive Upcall routine (see #03851)
 08h	DWORD	-> Transmit Upcall routine
 0Ch	DWORD	-> Event Upcall routine (see #03853)
 10h	DWORD	-> ASCIZ protocol name (zero if none)
 14h	WORD	protocol ID will be returned here (always non-zero)