[comp.sys.atari.st] DCD and RI detection

K538915@CZHRZU1A.BITNET (01/10/87)

UniTerm detects Data Carrier Detect thru polling bit 1 of the MFP 68901
IO port (Address $FFFA01), RI (Ring Indicator) is bit 6 (starting with
bit 0)..if you can think of something intelligent to do in a interrupt
handler, you can enable the corresponding MFP interrupt. A resonable
source for this kind of information (even if it does has errors) is
the Data Becker / Abacus book ST Internals, one good reason to buy it
(at least here) is the Bios/XBios listing in it...the latest edition
has a lot of errors corrected and is updated for ROM TOS.

                         Simon Poole