How do SCSI drives in the 3/160 tower communicate?

[AARON KONSTAM]

I have a question about disk connections to theSCSI bus in a 3/160, and I
assume other Suns with towers. Our 3/160 has two Micropolis 1355 internal
disks in its tower together with an Emulex controller to control them. We
also have a WREN VI drive in a shoebox connected directly to the SCSI
board in the tower with a ribbon cable.

According to the block diagrams that I have seen for the 3/160 the SCSI
board should be connected to the VME bus (and it is through three edge
connectors) and the Emulex controller in the tower should be connected
between the SCSI board and the disk drives. I can find no conections on
the SCSI bus except the edge connectors to the VME bus and the ribbon
cable to the shoebox.

How are the the Micropolis 1355 which are supposed to be SCSI disk drives
getting control signals from the SCSI bus? I will have to admit the
machine works with out my understanding this but if someone could clear up
this mystery I would appreciate it.

AARON KONSTAM
Trinity University
715 Stadium Dr.
SAN ANTONIO, TX 78212
(512)-736-7484
AKONSTAM at TRINITY.BITNET