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Path: utzoo!utgpu!lansd
From: lansd@utgpu.UUCP
Newsgroups: comp.sys.atari.st
Subject: Reading CD from RS232 port
Message-ID: <1987Jun13.214112.4171@gpu.utcs.toronto.edu>
Date: Sat, 13-Jun-87 21:41:12 EDT
Article-I.D.: gpu.1987Jun13.214112.4171
Posted: Sat Jun 13 21:41:12 1987
Date-Received: Sat, 13-Jun-87 22:35:17 EDT
Organization: University of Toronto Computing Services
Lines: 7
Keywords: rs232 dcd
Checksum: 65451

    Could someone describe how to read the status of the Carrier detect
bit on the RS-232 port. This is the first time that I have had to address
the hardware directly in the Atari and am not sure how to go about it.
    My guess was to go into the supervisor mode and access the MFP
chip register directly (I don't wan't to enable the interrupt vector, as
I have to time the transitions on the DCD bit accurately). There doesn't
seem to be any BIOS calls to access the MFP registers.