At 4:22 PM -0500 10/2/00, Eric Damien Berna wrote:
>I'm not sure if you can use a drive with an 80 pin connector and use 
>an adaptor.  I think the drives with the 80 pin connectors are wide 
>devices, that is they have twice the data lines that allows faster 
>data throughput.  If the drive can sense that it is connected to a 
>narrow cable, maybe it will work correctly.  I suggest trying to 
>find a 50 pin hard drive.

Wide transfers need to be specifically requested on the interface and 
the interface is supposed to fall back to narrow.  Of course a 
specific drive may not implement this feature properly and some wide 
to narrow cables/adaptors may not properly terminate the extra data 
lines.

The 80-pin connector is what's called an SCA interface.  The idea is 
that things like SCSI ID are to be determined by where the drive is 
plugged in.  You will need an appropriate adaptor and the physical 
space for the adaptor inside the Mac case.  The adaptor will have dip 
switches to set the SCSI ID on it as well as both the power and 
interface sockets, and maybe other options.  Usually the adaptors go 
80-pin to 68-pin wide (and power), but I have seen some advertised 
that provide both 68 and 50 -pin sockets.  Sounds bulky.

That said it should "work".  I was running a wide-to-narrow adaptor 
inside a 7500 for a while.  It just barely fit and the interface 
wouldn't negotiate a synchronous transfer speed so it worked slowly. 
I wasn't happy with having what should have been my fastest drive 
actually be the slowest.

Given a choice I think you are best off getting a drive whose 
capability matches what the computer provides.  Similar generation 
SCSI interfaces are most likely to perform optimally, but you can 
probably get most conceivable combinations to work.


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