INT 21 - Novell NetWare - WORKSTATION - SET PRIMARY CONNECTION ID
        AX = F004h
        DL = connection ID of primary file server (1-8) or 00h for none
Note:   this function is supported by Advanced NetWare 2.0+
SeeAlso: AX=EF03h,AX=F000h,AX=F002h,AX=F005h