I think I am having some termination problems on my Cyberstorm PPC scsi.
Here's what I have:
A short SCSI cable with a terminator on the end (how do I tell if it's Active?!?), one connector in the middle, then one at the other end.
So I have:
End of cable Terminator --> CS PPC <-- ACARD 7720UW SCSI-to-IDE and then my IDE drive.
This is your problem. I have yet to find any UW scsi device which has built-in active termination - they are all passive in my experience.
For the CSPPC UW-SCSI with one device you need a minimum of four connectors on your 68-way SCSI cable:
1 - Active terminator
2 - CSPPC SCSI header
3 - Device
4 - Active terminator
The ACard
UW SCSI-IDE adapter (AEC 7720UW) is a 16-bit device - this is what your cyberstorm is communicating with (The IDE device attached is irrelevant as far as the cyberstorm is concerned).
The only jumpers on the ACard are Terminator Enable and Terminator Power. Both are enabled.
The
ACard manual does not specify if the built-in-termination is active or passive, and the lack of components on the board (compared to an active terminator) suggests passive. This is the most likely cause of your problems.
I would strongly recommend that you get yourself two active terminators. I've used ones similar to
these with no problems (although they looked slightly different) - the key is that it is 68-pins wide, and supports SE (single ended) modes, as the CSPPC operates SE only, not L/HVD (low/high voltage differential). Consequently all attached devices must support SE modes.
Once these are attached to each end of the chain, disable any termination on other devices (eg the ACard adapter).
Activating termination Power on multiple devices will not do any harm, but you shouldn't need to activate it on more than one device in the chain.
-I *HAVE* to set the bus-width to 8-bits. If I set to 16-bits I get a parity error message from the cybppc.device (under os 3.9).
-The drive works fine in OS 3.9, set to 8-bit synchronous.
-I *have* had a lockup under OS 3.9 from which I think was a SCSI lockup.
All of which are probably due to poor termination.
-The drive is NOT detected under OS 4.0 after the OS4 kernel loads and the machine reboots. The OS4 cybppc.device scans the SCSI bus but does not detect any devices.
Perhaps the OS4 driver is more picky - I have no insight here.
Regards
Rich
PS - I've set up SCSI chains several times on CSPPC, and currently have (in storage) a CSmk3 with SCSI chain (set up as described above) and ACard 7720UW adapter working perfectly.
PPS - You
can mix 8-bit and 16-bit devices on the same bus, but both ends of the chain must still be actively terminated on all 16-bits. This is done by essentially extending the lower 8-bits into another chain (but you must actively terminate them also). Eg:
1 - Active terminator
2 - CSPPC SCSI header
3 - Device
4 - Upper 8-bits Active terminator (leaving lower 8-bits unterminated)
(8-bit chain continues)
5 - 8-bit device
6 - Lower 8-bits Active terminator
This is a more complex thing to try AFTER you have a simple (ie all 16-bit) chain up, running and stable. It's not a configuration I would recommend for early troubleshooting!