31 Aug
2004
31 Aug
'04
6:53 a.m.
On Aug 31, 2004, at 10:29 AM, Pete Turnbull wrote:
On Aug 31 2004, 0:44, Ron Hudson wrote:
Here's the schematic from the site You mentioned...
==============
A "O" means a connection
PIN NUMBERS ARE FOR MAC DB-9.
NUMBERS IN () ARE FOR MINI DIN 8 (MAC PLUS)
CapNet Connector (last update 8/21/90)
J1 J2
9 (5) C1 .1 uF
RCV(-) ----------------------------O----------][------O <myx>
!
8 (8) ! C2 .1 uF
RCV(+) --------------------------------O------][------O <myy>
! ! ^
! ! TO
5 (3) 10 ohm ! ! "PHONE"
TX(-) -----------O-----------R3---- ! LINES
! !
4 (6) ! 10 ohm !
TX(+) -----------------O-----R4--------
! !
1K R R 1K
1 2
! !
3 (4) ! !
GND -----------O------
PARTS LIST:
QTY DES ITEM
2 R1,2 1K 1/8W RESISTORS
2 R3,4 10 OHM 1/8W RESISTORS
2 C1,2 .1 uF THREE LAYER CERAMIC CAPS
1 J1 DB-9 MALE OR MINI DIN 8 CONNECTOR
1 J2 2 PIN BERG OR RJ-11 PHONE CONNECTOR
5 WIRE (NOT SHOWN) 22 GAUGE STRANDED WIRE 6"
==============================
I assume I connect all the <MYX> together and all the <MYY> together to
actually join the
machines..
Since all 3 items are sitting in one place, I will probably build a
small PCB with 3 parts
of 2 printer cables cut in half.
I am currently using an Imagewriter printer cable
to hook up one
device, and that
seems to work ok, and there is no electronics there.. Perhaps the
transformers are
for some safety - decoupling purpose?
You have the equivalent of a point-to-point link, with Tx on one device
connected to Rx on the other. When you have things set up as a
network, all the Txs go onto a bus that connects all the Rxs. The
transformers allow the signals to combine, and separate them for each
station.
But I'd expect you could just find some proper boxes easily and cheaply
enough; they're not rare, even here in the UK.
--
Pete Peter Turnbull
Network Manager
University of York