gkn@SDS.SDSC.EDU.UUCP (06/07/87)
Mike: Your problem is PADDING, a hack whereby the first two bytes of the data portion of the ethernet frame are used to contain the length. Prior to VMS V4.5, the DEUNA driver (XEDRIVER) assumed that padding was ENABLED, even for promiscuous mode UCBs. If the value in the first two bytes of the data portion of the frame is sufficiently large, and the CXB falls near the end of non-paged pool, you'll get an ACCVIO in routine MOVBUF (called from IOC$IOPOST, in module IOPOST) when VMS goes to copy the buffer back to your address space. The solution is to disbable padding on the promiscuous mode unit, which is done with the parameter NMA$C_PCLI_PAD (2842 decimal). $NMADEF is in the macro library SYS$LIBRARY:LIB.MLB, by the way. gkn -------------------------------------- Arpa: GKN@SDSC.ARPA Bitnet: GKN@SDSC Span: SDSC::GKN (27.1) USPS: Gerard K. Newman San Diego Supercomputer Center P.O. Box 85608 San Diego, CA 92138 AT&T: 619.534.5076