Subject: Re: (OFF-TOPIC) hardware SCSI termination?
To: Ken Nakata <kenn@remus.rutgers.edu>
From: Nathan Raymond <nate@staff.feldberg.brandeis.edu>
List: port-mac68k
Date: 11/17/1997 14:14:50
On Mon, 17 Nov 1997, Ken Nakata wrote:

> On Mon, 17 Nov 1997 10:55:39 -0500 (EST),
> Nathan Raymond <nate@staff.feldberg.brandeis.edu> wrote:
> > On Mon, 17 Nov 1997, Ken Nakata wrote:
> > 
> > > On Mon, 17 Nov 1997 02:05:18 -0800 (PST),
> > > SamMaEl <rimsky@teleport.com> wrote:
> > > > to terminate itself, but what sort of place would I be able to get a
> > > > terminator jumper that would be able to terminate my drive? Preferably
> > > > something cheap ;-)
> > > 
> > > If you want something really cheap, you can wrap up the jumper posts
> > > with thin copper wires.  Try not to short circuit nearby circuits.
> > > 
> > > Real jumpers (those square plastic things with a pressed metal sheet
> > > embedded), I have no idea where to get, but I would imagine mail-order
> > > electronics places like JDR might carry them.
> > 
> > Its a terminating *resistor*, not a jumper, that he needs.  They have
> > about 8-10 prongs, and go in one way (typically indicated by a white dot
> > on one end of one side which lines up with an arrow on the hard drive PCB
> > board).
> 
> Ah, a resistor network block.
> 
> I don't know anything about his drive, but most drives sold these days
> have either a jumper or a DIP switch to configure the drive
> termination.  The thing typically packaged in a 18-pin, 300mil wide
> ceramic DIP is becoming a thing of the past.
> 
> Ken

Actually, it depends on the drive manufacturer.  I've seen recent Quantum
mechanisms using two or three resistor strips (each with 8-10 legs or so,
don't have any in front of me) inline right next to the SCSI connector on
the drive mechanism. 

Connor drives I've never figured out. (The one Conner drive I have has a
"network block" type thing that looks like it might be the terminating
resistors, I don't know.)

--
Nathan Raymond