CTS/RTS hardware handshake for GS
Mini-Din 8 DB-25 (RS-232 Male)
Female Male 01 02 03 04 05 06 07 08 09 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24 25
8 7 6 6 7 8
5 4 3 3 4 5 DB-25 (RS-232 Female)
2 1 1 2
13 12 11 10 09 08 07 06 05 04 03 02 01
25 24 23 22 21 20 19 18 17 16 15 14
DIN-8 DB-25 Signal Discription
3 2 TD (Transmit Data)
5 3 RD (Receive Data)
4,8 7 GND (Ground)
2 5 CTS (Clear to Send)
1 4,20 RTS (Ready to Send) (20 = Data Terminal Ready, DTR)
7 8 DCD (Data Carrier Dectect)
The wiring for a GS-serial-port and a modem,is as follows:
GS serial port Modem
1....>>...........DTR..............20
2.................DSR......<<.......6
3....>>...........TxD...............2
4.................GND...............7
5.................RxD......<<.......3
7.................DCD......<<.......8
1.The arrows mark the direction of the signal (i.e,DTR is output from the
modem into the computer etc,).
2.The numbers for on the GS port column assume the following numbering on the
connector:
+++# #+++
+ #__# +
+ 8 7 6 +
+ +
+ 5 4 3 +
+ +
+ 2 1 +
### ###
+# #+
++++
3.The numbers on the modem column assume the standart DB-25 RS232 connector.
As to 'minimal connection',I don't think there are many modems that would
compromise on DTR.Anyhow,lack of DSR and DCD is usualy more tolerable.
TxD+/TxD- and RxD+/RxD- is part of the glorious RS 422 concept,and more
accurately,of a method called 'differencial signal'.In this method,for each
of the Receive and Transmit signals,one wire carries the signal just as it
would on RS 232,and a second wire carries the first's inverse polarity.(Thus
the couples xD+/xD-).Now,the receiving device compares the xD+ to it's
inversed partner.If xD+ is higher than xD-,the receiving device reads 'high',
if it's lower,the device reads 'low'.What you get is a speed considerably
higher than on RS 232,and a connection much more emmune to noises.
You'll have to work out the appropriate Control-Panel configuration according
to the modem and software you use.
Yoram Ney
Hebrew University,Jerusalem
Bitnet:NEY7@HBUNOS
From pro-freedom!pro-ren!pro-applejacks!terry%clark.edu@mail4.engin.umich.edu Wed Jun 16 05:21:23 1993
Received: from srvr2.engin.umich.edu by mail4.engin.umich.edu (5.64/1.35)
id 6090306cf.0017b7e; Wed, 16 Jun 93 05:21:19 -0400
Received: from crash.cts.com by srvr2.engin.umich.edu (5.64/1.35)
id AA18626; Wed, 16 Jun 93 05:21:16 -0400
Received: from clark.edu by crash.cts.com with smtp
(Smail3.1.28.1 #15) id m0o5tg8-00005wC; Wed, 16 Jun 93 02:21 PDT
Received: by clark.edu (Smail3.1.28.1 #1)
id m0o5tcF-0000ZBC; Wed, 16 Jun 93 02:17 PDT
Received: by pro-freedom.van.wa.us (sendmail 2.3.1 7jun93)
id