CS PPC SCSI advice??

[HammerD]

*** UPDATED **** SOLVED:

-Updated ACARD AEC-7720UW FIRMWARE to latest version!
-Now 16-bit Synchronous mode works with exact same drive and cable
-Now 30MB/sec measured with SysSpeed!!!!!

Wow!

***********************8

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.

The only jumpers on the ACard are Terminator Enable and Terminator Power.  Both are enabled.

My problem:

-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.

-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.

Any ideas?!? thanks

[HammerD]

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.

The only device on the chain is the ACard UW-SCSI to IDE adapter with an IDE hard drive attached to it.  

The one end of the cable has the active terminator (at least I think it's an active terminator, I don't know how to tell), the middle connector is connected to the CS PPC scsi, and the other end of the cable is the ACARD with IDE drive.  Terminator is set to enable on the ACARD and also Terminator Power is Enable.  

So I'm not sure what else to do.

[HammerD]

Was I correct about the BlizzardPPC cards  on the A1200 though ?

You are correct Blizzard SCSI is not supported under OS4.

Back to my thread...anyone else have any ideas on my CS PPC SCSI problem?

[HammerD]

Do you have a regular SCSI drive that you can test with? Might be something with the Acard termination indeed.

I've had similar problems with my CSPPC (now sold) when termination was messed up. Worked like a charm with an SCA drive with SCA-UW adapter and a terminated cable, similarly setup to yours.

Running on a 'regular' SCSI disk can determine where your issue is!

Yes I have a regular drive I could test it with.

So, if I remove the ACARD, and put on a UW SCSI drive, should I enable both Termination Power  (sometimes there is Termination Power "To" or "from" drive), and then Terminator Enable.  

I think Setting Terminator (on the drive) to enable is a no brainer.  And I would assume that Termination Power (from drive) is also correct?

[HammerD]

Finding UWSCSI drives with termination is difficult. I have a SG with termination and the other end of the chain is terminated with an active terminator; the drive delivers termination power. No problems with the chain - there are total 3 drives.

And you can use 16-bit Synchronous no problem? How much MB/sec transfer rate do you get? (you can measure with SysSpeed).?

[HammerD]

If I remember correctly "Termination Power" is not that big of a thing. You need it somewhere on the bus and (again, if memory serves me right) the CSPPC does that for you.

Most more modern drives feature "Auto Termination" and have no jumpers to set or unset it.

I would try it out with the UW drive on one end, CSPPC in the middle, ribbon/cable terminator at the end. And check the settings in the bootup screen (was that CTRL+S ?)

It's ESC to get to the CS PPC Boot menu where you can adjust SCSI settings.  I have to set it to 8-bit currently otherwise the drive is not recognized.

I will try looking at the jumpers on the drive tonight, and also test the ACARD by removing the Termination Power jumper.

Thanks for the tips.

[HammerD]

Yes - one drive must be forced into it as automatic doesn't work. 28-31 MB/s.

Wow that's great speed....wish I could get that...first I have to get it properly setup, but even then, I think my drive isn't fast enough for that.

[HammerD]

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

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]

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.

Ideally I want to use 16-bit synchronous with the ACARD and nothing else on the chain.

I thought that having an active terminator -- CS PPC -- ACARD with term power and term enabled was enough.

[HammerD]

Like I wrote Seagate had some models with active term - I have one on my chains end and it works fine. The other end is with an active terminator.

How do you know it's active terminated?  

The jumpers never say "active" at least on my seagates.  It's always

Terminator (enable/disable)
Termination Power from Drive (enable disable)
Termination Power to Drive etc etc....

What model of seagate do you have?

[HammerD]

I found this on Seagate's site.  Indicates that the Seagate drives after 1994 have active termination via the TE jumper:

SCSI Termination
Options
11-11-2007 02:21 PM

With today's high speed hard drives combined with long cable runs, only use high quality 'twisted pair' cable and external active (cable end) terminators. Active termination boosts data integrity and reliability. With active termination, a 110-ohm resistor on each signal line connects to a voltage regulator. The regulator ensures signal quality over the entire length of the SCSI bus. This reduces under and overshoot signals typically found on passive resistor termination schemes
Passive termination draws its electrical power from the SCSI host adapter. A 220/330-ohm resistor is used to provide the necessary impedance to prevent the data signal from 'reflecting' back. Fluctuations in termination power (or failing cables) can show up as error symptoms in the drive, yet do not originate there. In general we recommend you enable SCSI Termination Power if available.
Seagate, Maxtor (and Quantum) SCSI disk drives have either onboard active termination (jumpers). Older drives (circa 1994) enable active termination by two removable (10-pin) termination resistors. Some use passive termination with three removable (8-pin) terminating resistor packs. Seagate does not supply terminating resistor packs for older drives.
SCSI Single Ended Hard drives using active onboard termination have a jumper setting labeled 'TE' to control the termination setting.
All Quantum Single-Ended SCSI drives ship defaulted to provide SCSI Termination Enable.
SCSI LVD (low voltage differential) drives do not supply SCSI Termination Enable. Refer to the drive configuration guides for proper setting of this feature.
Notes:
Some Seagate and Quantum SCSI disk drives are available in both Single-Ended and LVD versions. Specifically, the Atlas III and Viking II drives offer both types of termination. Atlas III Narrow (50 pin) drives are Single-Ended, while the Wide (68 pin) and SCA (80 pin) versions are LVD models. Viking II Wide drives are available in both SE and LVD models. The part number for an SE drive will contain ‘W’, and the LVD will contain a ‘L’ (e.g. PX09L011 would be LVD). All Viking II SCA drives are LVD models. All fifty pin Quantum SCSI drives are all SCSI Single-Ended.
LVD cables and SCSI bus terminators can be purchased from Granite Digital, CS Electronics, TMC , or a local retailer.
Use due diligence when installing or adding SCSI devices. Unlike most electronic devices, SCSI may operate if improperly terminated, but performance and reliability will be seriously at risk.



I guess in the case of my A4000T with SCSI hard drive I would have:

ACTIVE Terminator --> CS PPC <-- Seagate ST39173W.  

On the Seagate hard drive I would have TE (terminator enable) jumpered and also Terminator Power From Drive.

I'm not sure about Parity - do I need that enabled?  There is a jumper on the drive for "Enable Parity check of SCSI Bus".  The Default is "enabled".


For my  A4000 desktop system with the ACARD:

ACTIVE Terminator --> CS PPC <-- ACARD with Terminator Enabled and Terminator power Enabled, then my IDE drive attached.

I'm still not 100% sure if I need an extra active terminator after the ACARD....some people don't seem to have them.

[HammerD]

There's some good information in there, given that you have a ST39173W, which would indicate that this is equipped with activer termination. If so, great.

Re your LVD/320 terminator, LVD is a totally different SCSI mode which is incompatible with SE (single ended). The termination specifications are different (see wikipedia page on SCSI). The Cyberstorm PPC is SE - not LVD. The terminators I have bought in the past have specifically supported both LVD and SE buses. Your LVD/320 terminator may not support SE buses - I cannot say. However, if you have two of the Seagate drives with active termination you could perhaps try one of these at each end of the chain.


Looks good, assuming that the LVD/320 terminator also supports SE buses (see above).


You can try with/without on this one - it will do no harm.

If there is a 'Force SE' jumper, you may as well activate it (CSPPC SCSI is a SE bus)



The ACard bridges may - or may not - have active termination. I do not remember if I have  tried the termination on them.
However, I've tried with various hard drives and CD/DVD drives with built-in termination over the years, and nothing has ever worked as well as proper dedicated terminators for me. also, nothing comes close in terms of reliability (and simplicity of troubleshooting if things DO go wrong) as having the correct setup in the first place.
Also, SCSI buses which are not terminated can still work - albeit less reliably, with more data corruption, more chance of bus lockups, etc, etc, etc. It's so particular to each setup: cable length (wrt bus frequency and phase of reflected pulses), spacing between devices, etc.  

The CyberstormPPC scsi bus is a tricky beast even when set up correctly.

No doubt. Thanks for your advice.  I've already found out that the OS4 cybppc.device is less forgiving than the phase-5 cybppc.device used under OS 3.x.  I've had my system working fine (or what I thought was fine) under OS 3.9 only to find out the OS4 cybppc.device doesn't find anything.

I'll do some more verification on the ACARD AEC-7720UW - I've emailed their tech support to ask about active termination.   I will also double check my terminators and cables to make sure they are SE or LVD/SE.  I have 3 cables but I think only two of them actually have any labeling on the terminators, the other one I think there isn't anything to tell me if it's LVD or SE, but i would assume SE if not specifically labeled LVD.