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Author Topic: CS PPC SCSI advice??  (Read 8589 times)

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Offline x56h34

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Re: CS PPC SCSI advice??
« on: September 29, 2010, 04:17:20 PM »
Quote from: HammerD;581892

Any ideas?!? thanks


Sounds like now that your bus is 8-bit, and your terminators are 16-bit wide, you are terminating only the upper 8 bits, and not the lower 8-bits as required by the scsi II standard.

You need two 8-bit active terminators on ech end of the scsi chain, or convert back to 16-bit and go UW-SCSI only, that is asuming that all the devices in the chain are UW-SCSI (16-bit) compliant/compatible and that your terminators are active/correct type.
 

Offline x56h34

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Re: CS PPC SCSI advice??
« Reply #1 on: September 30, 2010, 03:44:00 PM »
Quote from: HammerD;582084
Ok thanks for your detailed reply.   Regarding my other system (not the one with ACard) I have a what I believe is an active terminator on the end of the cable (it says LVD/320) which I believe all are "Active", in the middle is the CS PPC, and the other end a Seagate 9.1GB UW Drive model  ST39173W.   That drive has jumpers:

Enable SCSI Terminator (enable or disable)
Term. Power from Drive (enable or disable)
Term. Power to SCSI Bus (enable or disable)
Drive Furnishes power both to its own terminators and to the SCSI Bus (if both enabled)
Term. Power from SCSI Bus (enable/disable)

My assumption here is that "Term Power" means "Active".

Also my assumption would be you should enable  SCSI Terminator, Term Power From Drive and Term Power to SCSI Bus.  

Do you think that is correct? The CS PPC manual says nothing about these jumpers they only talk about "Active" Termination.  But I assume applying power means "Active".


HammerD,

Your bus is set to 8-bit.

Your terminators (both ends) are terminating upper 8 bytes only. This is what they are designed to do and this is why you ran into, with this issue.

You need terminators that terminate lower 8 bytes. Your existing terminators will not terminate anything but upper 8 bytes (by design).

Your chain must look something like this:

active term (low 8 b) --- CSPPC --- Hard Drive + acard with term power enabled and termination disabled --- active term (low 8 b).

You might need to aquire a longer cable for your particular setup / hardware, due to the acard thingy being at one end of the chain.

You also might need to clarify with the manufacturer if the UW acard can successfully fallback to SCSI-II levels.