mjb%hoosier.utah.edu@cs.utah.edu (Mark Bradakis) (12/05/89)
Hope I am not trying to give mouth to mouth to a long dead horse here, but I have what I think are simple qusetions about the SCSI port on the Personal Iris. Am I correct in thinking that it is a single ended (vs. differential) async port, with sync capability in 3.2 software? Assuming the scsi_setsynch or whatever value is correct. I tried plugging a SCSI disk onto the machine, and got many many SCSI hardware errors while booting. Thanks for any info. mjb. mjb@hoosier.utah.edu "If I took a rollin' wheel, rolled it ten times 'round..."
olson@anchor.sgi.com (Dave Olson) (12/05/89)
mjb%hoosier.utah.edu@cs.utah.edu (Mark Bradakis) writes: >Hope I am not trying to give mouth to mouth to a long dead horse here, >but I have what I think are simple qusetions about the SCSI port on >the Personal Iris. Am I correct in thinking that it is a single ended >(vs. differential) async port, with sync capability in 3.2 software? >Assuming the scsi_setsynch or whatever value is correct. All SGI machines currently are single-ended SCSI. Differential might be supported some day, but there are relatively few devices today that require (or support) it. Synchronous SCSI support is in all 3.2 systems, but enabled by default only on the 4D20 and 4D25. This was due to some of our older systems SCSI cabling not being quite correct. There was concern that enabling sync mode on these systems would lead to many SCSI errors. >I tried plugging a SCSI disk onto the machine, and got many many SCSI >hardware errors while booting. Thanks for any info. >mjb. Sounds like you either had extra termination, or conflicting ID's. Internal SCSI drives are normally ID 1, the host adapter is 0, and tape drives are ID 2 (on 4D20, 25), or ID 7 on other machines. Terminators shouldn't be used on the 4D20,25 unless connected to the external SCSI port; on the other 4D machines, only the top SCSI device in the drive tower should have termination. Dave Olson It's important to keep an open mind, but not so open that your brains fall out. -- Stephen A. Kallis, Jr.