UltraLite RS232 port

Brian Smithson (brian@grot.ca41.csd.mot.com)
Sun, 5 May 91 07:21:16 PDT

A couple of notes about the RS232 port and cables
-------------------------------------------------

(1) The DB25<->DB9 adaptor which is supplied with the UltraLite is not wired
the same way as a standard PC/XT<->PC/AT serial adaptor. In addition to
the DB9 end being female instead of male, the wiring is different.

Here is the wiring:

DB9 DB25
--- ----
1 6
2 2
3 3
4 6
5 7
6 8,20
7 5
8 4
9 NC
S NC

[S=sheild, NC=no connection]

(2) The UltraLite serial cable has the following wiring with and without the
DB9 adaptor, referenced to the DIN connector:

DIN DB25 DB9 Function
--- ---- ---- --------
a 7 5 signal ground
b 8 6 carrier detect
c 20 6 DTR
d 3 3 receive data
e 4 8 RTS
f 5 7 CTS
g 6 1,4 DSR
h 22 NC ring indicator
i 2 2 transmit data
S S NC protective ground

[S=sheild, NC=no connection]

UltraLite DIN connector labels, as viewed from the pins:

a b c
d e f g
h i

I haven't yet been able to identify the DIN connector by model number or
DIN standard number. Has anyone else identified this connector and/or
found a source for spares?

-- 
-Brian Smithson
 Motorola Inc., Computer Group, Commercial Systems Division
 10700 N. De Anza Boulevard, Cupertino, CA 95014 USA, (408)366-4104
 brian@csd.mot.com, {apple | pyramid}!motcsd!brian