I am not sure if this is exactly on-topic, but i would be very grateful of any help you can offer. Basically, i think i have crippled the scsi controller on my boss's powermac 7200. (This occurred while trying to hook up an external scsi cd-writer to do some file movement to his new machine. I turned the burner on during boot, and also had it terminated. Both these are no-no's for the machine (although i am consoled by others that scsi SHOULD be hot swappable, and termination should not damage hardware). Local mac expert could not get it to boot off cd, so looks like controller is knackered.) Anyway, i have no access to other macs, and no way of knowing if the hdd is intact or not. What i do have is my linux box (Dell precision 410) with Adaptec 2940 U2W and Adaptec 2940 UW SCSI controllers on the motherboard. I know from reading around, that it should be possible to mount the disk if i can get it to work in the pc. what i don't know is how safe it is to do something like this (is the disk real scsi). Will i end up with two broken machines rather than one if i connect the drive to the pc controllers?! Things like the apple advice not to terminate external devices due to the internal hard drive being terminated do not give me confidence (seems at odds with all other scsi advice i have found).
I understand nobody can guarantee anything, but if anyone subscribed to this list thinks they know something relevant (like that i should not even think about this) then i would appreciate the advice. thanks michael
I'm sure your local mac expert tried this... but just in case, try zapping PRAM. I have had a Mac which wouldn't boot of CD, disk, whatever... turned out the PRAM was corrupt... If I recall correctly, that was just after hot-swapping a CD-R.
michael.conry@softhome.net wrote:
I am not sure if this is exactly on-topic, but i would be very grateful of any help you can offer. Basically, i think i have crippled the scsi controller on my boss's powermac 7200. (This occurred while trying to hook up an external scsi cd-writer to do some file movement to his new machine. I turned the burner on during boot, and also had it terminated. Both these are no-no's for the machine (although i am consoled by others that scsi SHOULD be hot swappable, and termination should not damage hardware). Local mac expert could not get it to boot off cd, so looks like controller is knackered.) Anyway, i have no access to other macs, and no way of knowing if the hdd is intact or not. What i do have is my linux box (Dell precision 410) with Adaptec 2940 U2W and Adaptec 2940 UW SCSI controllers on the motherboard. I know from reading around, that it should be possible to mount the disk if i can get it to work in the pc. what i don't know is how safe it is to do something like this (is the disk real scsi). Will i end up with two broken machines rather than one if i connect the drive to the pc controllers?! Things like the apple advice not to terminate external devices due to the internal hard drive being terminated do not give me confidence (seems at odds with all other scsi advice i have found).
I understand nobody can guarantee anything, but if anyone subscribed to this list thinks they know something relevant (like that i should not even think about this) then i would appreciate the advice. thanks michael
I'm sure your local mac expert tried this... but just in case, try zapping PRAM. I have had a Mac which wouldn't boot of CD, disk, whatever... turned out the PRAM was corrupt... If I recall correctly, that was just after hot-swapping a CD-R.
And there is also the small push-button on the PCB that is even better to zap PRAM than the key combo. It is somehwere in the back middle 1/9 of the PCB, and is red or black.
.x. ... ... Front - X marks approx area where to look for it if I remember right.
michael.conry@softhome.net wrote:
I turned the burner on during boot, and also had it terminated. Both these are no-no's for the machine (although i am consoled by others that scsi SHOULD be hot swappable, and termination should not damage hardware).
I turn my burner on and off while the system is up all the time; this doesn't cause a problem. Obviously, if it's not on when the system starts, my CD writer filesystem driver can't find it, so turning it on later is useless; but if it's on at boot, I can turn it right off (my unit has a very noisy fan!) and then on again when I want to use it.
You can have multiple terminators on the same end of the SCSI chain, and though this is incorrect, it has no impact on hardware whatsoever; the bus will just be physically terminated at the first terminator on that end of the chain, so nothing after it will be recognized (unless you have a mix of narrow and wide devices, and you use a narrow terminator which doesn't have the sense to terminate the high byte on the cable - this will leave data trailing through to the following devices, giving you false termination).
In any event, I sincerely doubt that anything you did cooked any hardware. The PRAM is probably screwed up (this is a Mac, after all), so Command-Option-P-R during a cold restart cycle should clear it.
What i do have is my linux box (Dell precision 410) with Adaptec 2940 U2W and Adaptec 2940 UW SCSI controllers on the motherboard. I know from reading around, that it should be possible to mount the disk if i can get it to work in the pc. what i don't know is how safe it is to do something like this (is the disk real scsi).
Yes, the disk is "real" SCSI. The same disks go into Macs as into any other system running SCSI.
Will i end up with two broken machines rather than one if i connect the drive to the pc controllers?!
No, certainly not if you don't try to write to the drive. However, you should be aware that different controllers low level format differently, and just because the drive was low leveled on the Mac might make it unreadable by your 2940 card(s). I recently upgraded a server with a 29040UW to a Compaq ProLiant with onboard SCSI. I needed to completely reformat the drives, as the Compaq couldn't even read them. So, the bottom line with your situation is that you can't tell reliably whether the drive is damaged unless you connect it to the same type controller that originally formatted it (e.g., another 7200 machine).
HTH -- Lewis ----------------------------------------------------------- Lewis G Rosenthal, CNA Rosenthal & Rosenthal Accountants / Network Consultants New York / Northern Virginia Team OS/2 / NetWare Users International -----------------------------------------------------------
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Lewis G Rosenthal -
Michael Breuer -
michael.conry＠softhome.net -
Povl H. Pedersen