Re: scsi connection

[Wayne Stewart <waynes@intergate.bc.ca>]

If you just have a bare drive then you'll need a SCSI enclosure which can be
picked up for a few dollars used or new from a Mac dealer for considerably
more.
If you already have the enclosure(case) then you need a SCSI cable, usually
one with 50 pin centronic connector on one end and a db25 on the other.
This is a pretty standard Mac SCSI cable.

Termination. The last drive on a SCSI chain  needs to be terminated even if
you're only using one drive. A drive can be terminated in 2 ways, the drive
itself can have terminating resistors on it or you can use an external
terminator
which usually plugs into the other connector on your SCSI enclosure.

Term Power: this is different from termination. Something on the SCSI chain
has to supply term power, either the drive, the interface or what's called an
Active Terminator. Apple SCSI cards didn't usually supply term power as they
came from the factory but can be modified to do so. Most but not all drives do
supply term power. Other than attaching an extra drive that supplies term power

or modifying the SCSI card you have the third option of getting an active
terminator. Active terminators aren't overly common but the diagnostic
terminators that many computer stores sell will also supply term power.



JMN wrote:

> Hello
>
>  How do I connect a scsi harddisk 50 pin connector cable to a apple II scsi
> 25 pin cable/connector. Can anyone tell me the pins assigment?. The disk as
> a terminator jumper. Do I need to connect anything else (power terminator)?.
> thank you.
> Jean