chris@com50.c2s.mn.org (Chris Johnson) (09/21/90)
I've been having some goofy problems with SCSI errors when I connect up an external device along with an Ancot SCSI-bus analyzer. I know all about the rules for lengths and terminations for SCSI. But what I want to know is, just what is Sun doing on the inside of the Sparcstation? After all, they've got the external SCSI connector, and two internal SCSI connectors. Which of those are terminated? Just the external? All three? And correspondingly, which of the two internal hard disks I have should be terminated? Both? Neither? Left? Right? A schematic of the CPU board would answer all my questions. From just looking at the thing, it looks like there is just one set of terminators soldered to the board, which would lead me to think neither of the internal drives should be terminated. Except Sun ships the normal one disk terminated. Which suggests the second disk should not be terminated, if the internal disk is providing the "host end" SCSI bus termination. Unless the internal SCSI sockets have their own driver IC's separate from the external SCSI connector. Which also might be true, given that they are on the opposite side of the CPU board, and SCSI stub lengths are supposed to be less than 10cm, and the board is quite a bit wider than that. Aaaaiieeeee! Does anyone know the correct answer? ...Chris Johnson chris@c2s.mn.org ..uunet!bungia!com50!chris Com Squared Systems, Inc. St. Paul, MN USA +1 612 452 9522