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From: cwr@crash.cts.com (Will Rose)
Subject: Re: Minicom Question
Organization: CTS Network Services (CTSNET), San Diego, CA
Date: Wed, 5 Jul 1995 06:03:57 GMT
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Sum Wu (keroppi@teleport.com) wrote:
: Oh! By the way, one more thing: I can use Minicom to login to my Linux
: box through a null modem cable. For example, I use Minicom from Minix to
: login to Linux, and then use Minicom from Linux to call my Internet
: provider. I just have no luck when /dev/tty1 is attached to a real
: modem :-(

Ok, that's an RS-232 control signal problem, without a doubt.  You
need to set up your modem to give the right signals to the interface
on power up; probably RTS/CTS, but if you check the RS-232 pin voltages
in the two cases, you'll see which are missing when you talk to the
modem.

To recap, RS-232 signals are 2 - TxD, 3 - RxD, 4 - RTS, 5 - CTS,
6 - DSR, 7 - signal gnd, 8 - DCD, 20 - DTR.  Logic 1 is -5 to -15
volts, logic 0 is 5 to 15 volts, and *a control line is false
when asserted*.  Use a voltmeter or an LED to check stuff out.

Will
cwr@crash.cts.com

