dc@dcpc.UUCP (Don Curtis) (02/14/90)
I got the Conner Technical Manual today...here's the official word on both drive parameters and jumper settings: Heads 4 BlocksPerTrack 26 Cylinders 788 BlocksPerDrive 81,952 BytesPerBlock 512 Jumpers E1 thru E4 E1 OUT...parity ENABLED IN...parity DISABLED E2 E3 E4 SCSI ID out out out 0 IN out out 1 out IN out 2 IN IN out 3 out out IN 4 IN out IN 5 out IN IN 6 IN IN IN 7 RP1,RP2 and RP3 are terminator resistor packs, located just behind the SCSI connector. Leave IN on the last drive and OUT on all other drives on the SCSI cable. OR leave OUT on all drives and terminate the cable itself. Now...that's the official word from Conner, here's my experience with a CP340 (actually 2 of them sitting here right now). Heads 4 BlocksPerTrack 26 Cylinders 752 BytesPerBlock 512 TotalBlocks 78,208 My drives do NOT have any terminator resistors on them, nor are there any sockets for them on the controller board. While the drive DID show up as SCSI 0 with E2-4 OUT, it was VERY flakey. It would only boot when it felt like it, and would go off-line at odd times for no apparent reason. Also, doing an ASSIGN command (NOT info command) showed DH2: thru DH8: as existing (with only 1 drive attached to the SCSI bus). Two drives on the cable would not work at all...either neither of them showed up...or both showed up as the same drive. Yes, they were jumpered for different ID numbers. Based on the message by Darrin (???) earlier...I reversed the sense of the above SELECT settings (that is...changed the "out" to "in" and vice versa) and put all jumpers IN. Drive again showed up as SCSI ID 0 and this time, ASSIGN only showed DH2: as existing. The flakieness was GONE...the drive works perfectly. Adding a 2nd drive works fine also. That's my drives at home. At work, we have an AT&T 3B4000 UNIX machine. It uses 2 Conner CP340's as paging disks for 2 of the processors. Those drives meet the published specs (788 cylinders) AND the drive select jumpers are as per the above table...the drives have all jumpers IN and show up as SCSI ID 7. These drives have terminator packs on the controller. The only conclusion I can draw from this is that there are two different versions of the CP340. One version has 788 cylinders and uses the jumper settings as above for SCSI ID select. The other has 752 cylinders and uses just the reverse of the above SCSI ID table. Presuming my 2 drives aren't atypical, it would seem that the way to tell the two types apart is whether there were or weren't terminator packs on the controller (or at least sockets for them). All the drives are labeled "CP 340" Anyone else have any ideas? Or is anyone from Conner on the net and would like to comment? -- /* ** Don Curtis ...boulder!tcr!dcpc!dc ** CompuServe 76703,4321 ** 76703.4321@compuserve.com ** dcpc!dc@tcr.UUCP */