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Re: Addressing a SCSI film-scanner - SUCCESS!

On Wed, 2006-03-08 at 13:49 -0600, Bruce Bales wrote:
> I kinda hate to jump in here where I haven't been in the loop before, but 
> unless scsi has changed in the last few years, as I remember, most scsi 
> devices have two connectors.  Either can be input and the other then is 
> output.  The scsi bus is serial - up to seven devices in a row.

It's a parallel bus, not serial.

> The last device has a terminator plug on it which electrically terminates
> the data lines with resistors.

Or some other method (doesn't have to be a plug), and it doesn't have to
be the last device, and it doesn't have to be resistors as such (active
termination isn't just resistors).

It's the transmission line (the cable) that needs terminating (at both
ends), not the devices.  You can plug anything in anywhere in between,
so long as the ends are properly terminated.

e.g. term ------ plug ------ plug ----- plug -------- plug ----- term
                 HDD         host       burner

> The other end of the bus is terminated on the scsi card.

It's important to check that it does.  Some cards do not terminate the
line, you have to take care of that yourself.

Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.

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