Message-ID: <966@vax135.UUCP>
Date: Fri, 15-Feb-85 09:44:41 EST
Article-I.D.: vax135.966
Posted: Fri Feb 15 09:44:41 1985
Date-Received: Sat, 16-Feb-85 06:23:56 EST
Organization: AT&T Bell Labs, Holmdel, NJ
Lines: 32
Standard NULL-MODEM
The following table gives the connections for the standard NULL-MODEM as
sold by most computer supply companies.
Use two DB25 connectors and a short piece of cable or some wire. Most are
sold with female on both ends but you can customize it for your needs.
CONN-A CONN-B
--------------
1 1
2 3
3 2
4,5 8
6,22 20
7 7
8 4,5
20 6,22
22 4,5
This will work with most modems without modification. I use a Hayes 1200
and this. I have also used an ATT made by Penril that neesd pin 20 (DTR)
at the modem end tied to 6 (DSR) of the same end. Others I know who use
various modems from acoustic couplers to direct connect types use it one
of the two ways.
Gene Sampieri
ATT-Bell Labs
...vax135!ees