🚀 go-pugleaf

Thomas F Lee <tfl@psp.co.uk> writes:
> I've got a Dell p90 with an Adaptec 2940w (fast/wide) differential

Differential, are you sure?


> controller.  Hanging off the narrow end is a Panasonic CD.  Hanging
> off the wide end is a 2gb IBM Fast/Wide drive.  We're trying to put
> in an HP 2GB Fast/Wide drive and are having significant difficulties.
> 
> When we try to add the HP drive in, the 2940 fails to see anything,
> the bios doesn't install and the system fails to load anything.
> Normally, the 2940 sees the IBM and PANASONIC but not the HP.

? 2940w isn't differential, only the AHA-1744 is AFAIK.
  (Differentials benefit, apart from breaking the bank balance,
   is to allow for *long* cable runs, usually external.


> HP kindly replaced the drive foc (PLUG FOR HP!) - no joy.

It's *that* HP drive ;)


> We've checked cables, drive settings and have tried every combination
> of adapter settings - all result in the failure to load the Adaptec's
> bios.
> This leaves termination.
> Both disk drives have NO termination packs or any jumper settings.

No jumper settings for Active Termination/Term Power etc.

- You probably need to get a Cable Active Terminator & put it on a 
  connector at the end of your chain. SMC, Simply and other places do 
  them, the 2nd is definately open on a Saturday. 
  norman@brunel.demon.co.uk may have one in stock too.

The 2940 wouldn't see the HP if the IBM was indeed terminated. I have
a feeling neither the HP nor IBM (ultrastar/deskstar?) have such.


> The wide scsi cable that came with the 2940 seems nothing special.  

o  What is the cable quality like, single-ended impedance of 80-110ohms;
   length? I don't think cable is the problem if it came with the 2940w.


> How is this bus terminated (and is this a possible cure?)?


It sounds like the wide end needs terminating.

o  Check how the narrow & wide-bus are set-up in the BIOS.
o  Check the bus is terminated at BOTH ends & not in-between etc ;)
o  Check parity etc is set
o  Check terminator power etc just in case
   (if, in the unlikely event, you're running everything as 50-pin F-S-2,
    the Panasonic will terminate the chain if resistor packs are fitted.
    However, I'd prefer an Active Terminator at one end at least).

o  Check SCSI IDs (just in case)
o  Try the HP on the chain with no IBM connected
   (setting termination, BIOS & SCSI-ID as appropriate)

o  See if there is a jumper for the HP which enables spin-up.

o  Unlikely, but, there could be a firmware problem on the 2940, HP / IBM.
   The word Seagate doesn't feature anywhere so you should be OK.


I've c/p to comp.periphs.scsi - there are HP & IBM people there.
(They may/may not need to know Adaptec BIOS version, HP & IBM model numbers)

You know what gets me, Adaptecs "BIOS loaded successfully!" message.
... Why the exclamation mark ... do they think it might not happen sometimes?
-- 
_____________________________________________________________________________
Julian A F Bradbury                         Web, Graphics & Scanning Services
Ergonomist; Human Factors & IT Specialist          http://194.72.60.96/www/3b