Scsi internal Drives and Jaguar on 9500 |
February, 28, 2003 12:04 PM |
bghiggins |
Hi, I thought I will give readers some of my experience with SCSI internal Drives. I have several 9500 that I have upgraded (G3/500) and wanted to install Jaguar on them. My original plan was to upgrade the scsi drives with 2 50 pin 9 GB drives from OWC. These drives are IBM DNES 309170 LVD drives with a OWC SCA 80-50 pin SCSI adapter. The drives come with termination which can be removed by taking off 3 termination blocks from the adapter. The internal SCSI chain in my system had a CDROM, plus the two drives the last drive on the chain was the terminated drive. I could never get this set-up to boot into OSX. Got a jiliion read/write errors before the installer aborted. I removed the unterminated drive and tried to install OSX on the terminated drive . No luck Eventually I removed the terminated drive and replaced it with a old 50 pin 2G IBM drive with OS9 that had jumpers for termination, and kept the unterminated 9G drive on the chain. This worked and I was able to install Jaguar. So the experience I got from my frustrated excercise is that termination of a scsi chain is very tricky and as others hav noted Jaguar is very sensitive to proper termination. Moreover even when a drive is supposed to be terminated and works with OS9 it may still not work with OSX. B |
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RE: Scsi internal Drives and Jaguar on 9500 |
March, 03, 2003 8:48 AM |
mb.saransk |
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I also had some boot problems when I replaced my terminated drive with a new Seagate 18g. While I had enabled the termination, I had set it to get power from the bus (default). No go! Make sure your termination drive provides the termination power so there is enough "juice" to properly terminate the chain - this is especially true of 68 pin systems. All Unix based systems are very particular about their SCSI chains. Mike Baker |
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RE: Scsi internal Drives and Jaguar on 9500 |
February, 28, 2003 3:50 PM |
tempest |
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You're having these problems because LVD drives require better -to-50 pin adapters than what OWC provides. You need one that will terminate the upper 8-bits, and this termination must happen even if the drive is not at the end of your physical SCSI chain. Check out the ones from transintl.com--that's where I got mine. |
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RE: Scsi internal Drives and Jaguar on 9500 |
February, 28, 2003 1:02 PM |
mbaulez |
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The internal scsi bus is a 10MB/s, it is the external limited to 5MB/s. I have a 9500 With G3/400 and three internal disks : 2x IBM DCHS04 ( 9 Go) and 1 IBM Ultrawide 160 IC35L018W (18Go) All are connected on the internal bus and they work fine , with no problem for booting onseveral system :Mac Os 10.2.4 is on the 18 Go. I do not try to put a speeder U160 scsi card because I think that this computer is (very) limited by the 50Mhhz motherboard bus and not by drive speed. |
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RE: Scsi internal Drives and Jaguar on 9500 |
February, 28, 2003 12:40 PM |
dgautrey123 |
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B, I have the same set up on my 7500 with G3 300MHz 8 gig IBM drive 80 to 50 pin adapted and and IBM 4 gig 50 pin, and it works just fine, from what I have learned 80 pin drives require termination of the upper SCSI chain, ID's 8 thru 15, most adapters do not supply the required termination, you have to place them in a chain with an older 50 pin drive at the end supply termination. You could probably get it to work with the two 80 pin drives by using an active internal 80 pin terminator but if you have it working now I would just go with what you have. David. |
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RE: Scsi internal Drives and Jaguar on 9500 |
February, 28, 2003 12:15 PM |
lei1 |
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Quite often the reason you will get a failed boot on the adapted drives is timing. They are in essence "too quick" during the mounting process for the slower internal SCSI bus on the 9500 (5MB/sec). This causes failed boots & errors.Some have had success by enabling the "spin delay" jumper on the adapted drives. Others simply buy an ultra-wide PCI SCSI card and abandon the much slower internal bus. There is little advantage to having U160 drives on a 5MB/sec bus anyhow. It seems a waste of the drives true capabilities. |