[rescue] Wide disk on Narrow bus, reprise

[Mark]

On 7 Feb 2008, at 00:18, Scott Quinn wrote:

>> Next, I tried installing a 50pin (F) to 68pin (F)
>> adapter in the 50 pin header on the motherboard.
>> Then, running a 68pin cable between the drive's
>> 68pin connector and the 68pin connector presented
>> by this adapter.
>>
>
> Terminated 16-bit at one end, I assume - should be good (see below)
>
>> Note that I had strapped the drive to "FORCE SE
>> MODE" to ensure it wasn't an LVD vs. SE issue.
>>
>
> Did you also jumper it to "force narrow/8-bit transfers"? I've had  
> several drives that refuse to auto-negotiate the width of the bus  
> (Fujitsus seem to be a common culprit). Jumper them 8-bit and they  
> start working.

I have quite a bit of experience of using wide discs on narrow busses,  
mostly in Macs and Amigas. In my experience, you need to get hold of 2  
things - a terminator for the end of the 50 pin ribbon (and a ribbon  
with a spare stop at the end) and a 68-50 pin adapter that terminates  
the upper byte at the back of the drive. In theory wide drives should  
drop to narrow automatically once the upper btye is terminated, but I  
guess Fujitsu had to be awkward ;)

All my 68-50 adapters have 'ACTIVE UPPER' embossed on the casing and  
all came from the same place that I asked specifically for that type.  
I've used many Seagate (Cheetah & Barracuda) and IBM Ultrastar drives  
this way in 50-pin machines relatively successfully. Quantum drives  
are touch and go, some of mine work on 50-pin legacy machines and some  
don't but the ones that don't have Dell or Compaq part numbers and  
drive IDs on them. To be frank I've never tried Fujitsu drives, I  
don't own any and nor do I want to (friends have had bad experiences  
with them even from new).

That's my 2p worth.

-- 
Mark Benson

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