Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!osu-cis!sppy00!jmv
From: jmv@sppy00.UUCP (Jim Vickroy)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Carrier detect on an IBM PC
Message-ID: <248@sppy00.UUCP>
Date: 3 Apr 89 13:03:48 GMT
References: <78402EJV103@PSUVM>
Reply-To: jmv@sppy00.UUCP (Jim Vickroy)
Organization: Online Computer Library Center, Dublin, Ohio.
Lines: 21

In article <78402EJV103@PSUVM> EJV103@PSUVM.BITNET writes:
=>
=>      I am working on a project and need to know which port to read to check
=>for a carrier detect.  Only using BASICA since speed is not necessary. Since

The register you need is the Modem Control Register (MCR) for the 8250. It's
located at port 0x03FE for COM1 and 0x02FE for COM2. Within the register look
at bit 7 (Receive Line Signal Detect (RLSD)).

hope this helps......

jim
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