Newsgroups: comp.periphs.scsi
Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!hybrid!torag!aimed!seachg!db
From: db@seachg.uucp (David Bell)
Subject: Re: internal scsi terminators?
Message-ID: <1991May6.152948.6362@seachg.uucp>
Keywords: scsi terminators dataMate
Reply-To: db@seachg.UUCP (David Bell)
Organization: Sea Change Corporation, Mississauga, Ontario, Canada
References: <2955@randvax.UUCP> <1991May3.120134.26459@cbnewsk.att.com>
Distribution: na
Date: Mon, 6 May 91 15:29:48 GMT

In article <1991May3.120134.26459@cbnewsk.att.com> brankin@cbnewsk.att.com (william.t.rankin) writes:
>
>Me too, but I'd like some directions on how to build a terminator
>plug given, say, a 50-pin centronics port.  Actually, the format
>of the connector is not important, just give me it in terms of
>pins.
>
>Anyone built such a beast?
>
A few companies sell these. One that we deal with is Technical Cable
Concepts, 714-261-2423. They have a DB-50 connector version and a SCSI-2
connector version. 

To build one yourself is possible but a lot of work. You have to terminate the
following lines: DB0, DB1, DB2, DB3, DB4, DB5, DB6, DB7, DBP, ATN, BSY,
ACK, RST, MSG, SEL, C/D, REQ, I/O. These lines are located on the following
pins: 2, 4, 6 ,8 ,10, 12, 16, 18, 32, 36, 38, 40, 42, 44, 46, 48, 50.
Each line has to be terminated via a 220 ohm resistor to 5 volts (available
via the termpwr signal on pin 26) and a 330 ohm resistor to ground (all of
the odd pins are connected to ground with the exception of pins 23, 25 and
27)

You are probably better off to just buy one.

BTW does anyone know of a SCSI-2 termination solution ? (by SCSI-2 I'm refering
to the new termination scheme of pulling up each signal via a 110 ohm
resistor to a regulated 2.85 volts, not just using the SCSI-2 type
connector).

Thanks in advance for any help.

-- 
Dave Bell

Sea Change Corporation
Mississauga, Ontario, Canada
UUCP: ...!uunet!attcan!seachg!db