diff --git a/src/Makefile.am b/src/Makefile.am
index da672d7..5704382 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -46,6 +46,7 @@ DATABITS_SRC = \
 	databits.h \
 	databits_ascii.c \
 	databits_binary.c \
+	databits_callerid.c \
 	databits_baudot.c $(BAUDOT_SRC)
 
 minimodem_LDADD = $(DEPS_LIBS)
diff --git a/src/Makefile.in b/src/Makefile.in
index f3da11b..88ee040 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -67,7 +67,8 @@ am__installdirs = "$(DESTDIR)$(bindir)" "$(DESTDIR)$(man1dir)"
 PROGRAMS = $(bin_PROGRAMS)
 am__objects_1 = baudot.$(OBJEXT)
 am__objects_2 = databits_ascii.$(OBJEXT) databits_binary.$(OBJEXT) \
-	databits_baudot.$(OBJEXT) $(am__objects_1)
+	databits_callerid.$(OBJEXT) databits_baudot.$(OBJEXT) \
+	$(am__objects_1)
 am__objects_3 = fsk.$(OBJEXT)
 am__objects_4 = simpleaudio.$(OBJEXT) simple-tone-generator.$(OBJEXT) \
 	simpleaudio-pulse.$(OBJEXT) simpleaudio-alsa.$(OBJEXT) \
@@ -228,6 +229,7 @@ DATABITS_SRC = \
 	databits.h \
 	databits_ascii.c \
 	databits_binary.c \
+	databits_callerid.c \
 	databits_baudot.c $(BAUDOT_SRC)
 
 minimodem_LDADD = $(DEPS_LIBS)
@@ -319,6 +321,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/databits_ascii.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/databits_baudot.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/databits_binary.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/databits_callerid.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fsk.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/minimodem.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/simple-tone-generator.Po@am__quote@
diff --git a/src/databits.h b/src/databits.h
index 0a71e6d..50a5da1 100644
--- a/src/databits.h
+++ b/src/databits.h
@@ -51,3 +51,8 @@ databits_decode_binary( char *dataout_p, unsigned int dataout_size,
 	unsigned int bits, unsigned int n_databits );
 
 
+unsigned int
+databits_decode_callerid( char *dataout_p, unsigned int dataout_size,
+	unsigned int bits, unsigned int n_databits );
+
+
diff --git a/src/databits_callerid.c b/src/databits_callerid.c
new file mode 100644
index 0000000..cfcc353
--- /dev/null
+++ b/src/databits_callerid.c
@@ -0,0 +1,178 @@
+/*
+ * databits_callerid.c
+ *
+ * Copyright (C) 2012 Kamal Mostafa <kamal@whence.com>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "databits.h"
+
+#include <stdio.h>
+
+/*
+ * Caller-ID (USA SDMF/MDMF) databits decoder
+ *
+ * Reference: http://melabs.com/resources/callerid.htm
+ */
+
+#define CID_MSG_MDMF		0x80
+#define CID_MSG_SDMF		0x04
+
+#define CID_DATA_DATETIME	0x01
+#define CID_DATA_PHONE		0x02
+#define CID_DATA_PHONE_NA	0x04
+#define CID_DATA_NAME		0x07
+#define CID_DATA_NAME_NA	0x08
+
+static const char *cid_datatype_names[] = {
+    "unknown0:", "Time:", "Phone:", "unknown3:",
+    "Phone:", "unknown5:", "unknown6:", "Name:",
+    "Name:"
+};
+
+static int cid_msgtype = 0;
+static int cid_ndata = 0;
+static unsigned char cid_buf[256];
+
+
+static unsigned int
+decode_mdmf_callerid( char *dataout_p, unsigned int dataout_size )
+{
+    unsigned int dataout_n = 0;
+    unsigned int cid_i = 0;
+    unsigned int cid_msglen = cid_buf[1];
+
+    unsigned char *m = cid_buf + 2;
+    while ( cid_i < cid_msglen ) {
+
+	unsigned int cid_datatype = *m++;
+	if ( cid_datatype >= CID_DATA_NAME_NA ) {
+	    // FIXME: bad datastream -- print something here
+	    return databits_decode_callerid(0, 0, 0, 0);	// reset
+	}
+
+	unsigned int cid_datalen = *m++;
+	if ( m + 2 + cid_datalen >= cid_buf + sizeof(cid_buf) ) {
+	    // FIXME: bad datastream -- print something here
+	    return databits_decode_callerid(0, 0, 0, 0);	// reset
+	}
+
+	// dataout_n += sprintf(dataout_p+dataout_n, "CID: %d (%d)\n", cid_datatype, cid_datalen);
+
+	dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
+				cid_datatype_names[cid_datatype]);
+
+	if ( cid_datatype == CID_DATA_DATETIME )
+	    dataout_n += sprintf(dataout_p+dataout_n, "%.2s/%.2s %.2s:%.2s\n",
+				m+0, m+2, m+4, m+6);
+	else if ( cid_datatype == CID_DATA_PHONE && cid_datalen == 10 )
+	    dataout_n += sprintf(dataout_p+dataout_n, "%.3s-%.3s-%.4s\n",
+				m+0, m+3, m+6);
+	else
+	    dataout_n += sprintf(dataout_p+dataout_n, "%.*s\n",
+				cid_datalen, m);
+
+	m     += cid_datalen;
+	cid_i += cid_datalen + 2;
+    }
+
+    return dataout_n;
+}
+
+
+static unsigned int
+decode_sdmf_callerid( char *dataout_p, unsigned int dataout_size )
+{
+    unsigned int dataout_n = 0;
+    unsigned int cid_msglen = cid_buf[1];
+
+    unsigned char *m = cid_buf + 2;
+
+    dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
+			    cid_datatype_names[CID_DATA_DATETIME]);
+    dataout_n += sprintf(dataout_p+dataout_n, "%.2s/%.2s %.2s:%.2s\n",
+			    m+0, m+2, m+4, m+6);
+    m += 8;
+
+    dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
+			    cid_datatype_names[CID_DATA_PHONE]);
+    unsigned int cid_datalen = cid_msglen - 8;
+    if ( cid_datalen == 10 )
+	dataout_n += sprintf(dataout_p+dataout_n, "%.3s-%.3s-%.4s\n",
+			    m+0, m+3, m+6);
+    else
+	dataout_n += sprintf(dataout_p+dataout_n, "%.*s\n",
+			    cid_datalen, m);
+
+    return dataout_n;
+}
+
+
+// FIXME: doesn't respect dataout_size at all!
+/* returns nbytes decoded */
+unsigned int
+databits_decode_callerid( char *dataout_p, unsigned int dataout_size,
+	unsigned int bits, unsigned int n_databits )
+{
+    if ( ! dataout_p ) {	// databits processor reset
+	cid_msgtype = 0;
+	cid_ndata = 0;
+	return 0;
+    }
+
+    if ( cid_msgtype == 0 ) {
+	if ( bits == CID_MSG_MDMF )
+	    cid_msgtype = CID_MSG_MDMF;
+	else if ( bits == CID_MSG_SDMF )
+	    cid_msgtype = CID_MSG_SDMF;
+	cid_buf[cid_ndata++] = bits;
+	return 0;
+    }
+
+    if ( cid_ndata >= sizeof(cid_buf) ) {
+	// FIXME? buffer overflow; do what here?
+	return databits_decode_callerid(0, 0, 0, 0);	// reset
+    }
+
+    cid_buf[cid_ndata++] = bits;
+
+    // Collect input bytes until we've collected as many as the message
+    // length byte says there will be, plus two (the message type byte
+    // and the checksum byte)
+    unsigned int cid_msglen = cid_buf[1];
+    if ( cid_ndata < cid_msglen + 2)
+	return 0;
+
+    // Now we have a whole CID message in cid_buf[] -- decode it
+
+    // FIXME: check the checksum
+
+    unsigned int dataout_n = 0;
+
+    dataout_n += sprintf(dataout_p+dataout_n, "CALLER-ID\n");
+
+    if ( cid_msgtype == CID_MSG_MDMF )
+	dataout_n += decode_mdmf_callerid(dataout_p+dataout_n,
+						dataout_size-dataout_n);
+    else
+	dataout_n += decode_sdmf_callerid(dataout_p+dataout_n,
+						dataout_size-dataout_n);
+
+    // All done; reset for the next one
+    databits_decode_callerid(0, 0, 0, 0);
+
+    return dataout_n;
+}
+
diff --git a/src/minimodem.1.in b/src/minimodem.1.in
index 4d8d7e6..53bcc88 100644
--- a/src/minimodem.1.in
+++ b/src/minimodem.1.in
@@ -43,6 +43,32 @@ transmit mode: generate audio tones
 .TP
 .B \-r, \-\-rx, \-\-receive,  \-\-read
 receive mode: decode audio tones
+.SH {baudmode}
+The required \fI{baudmode}\fR parameter may be any floating-point value to
+specify a baud rate, or any of the special keywords listed below.
+The \fI{baudmode}\fR also implies certain other parameter defaults
+depending on the rate, including standard (or at least reasonable)
+default mark and space tone frequencies.
+.TP
+.B  {any floating point value N}
+: Bell202-style at N bps \-\-ascii
+.TP
+.B    1200
+: Bell202 1200 bps \-\-ascii
+.TP
+.B     300
+: Bell103 300 bps \-\-ascii
+.TP
+.B    rtty
+: RTTY 45.45 bps \-\-baudot \-\-stopbits 1.5
+.TP
+.B    same
+: SAME 520.83 bps \-\-startbits 0 \-\-stopbits 0 \-\-sync-byte 0xAB
+.br
+	NOAA Specific Area Message Encoding (SAME) protocol
+.TP
+.B    callerid
+: Bell202 1200 bps Caller-ID (MDMF or SDMF) protocol
 .SH OPTIONS
 .TP
 .B \-a, \-\-auto-carrier
@@ -146,29 +172,6 @@ Run and report internal performance tests (all other flags are ignored).
 .TP
 .B \-V, \-\-version
 print program version
-.SH {baudmode}
-The required \fI{baudmode}\fR parameter may be any floating-point value to
-specify a baud rate, or either of the strings "rtty" or "same".
-The \fI{baudmode}\fR also implies certain other parameter defaults
-depending on the rate, including standard (or at least reasonable)
-default mark and space tone frequencies.
-.TP
-.B  {any floating point value N}
-: Bell-syle N bps \-\-ascii
-.TP
-.B    1200
-: Bell202 1200 bps \-\-ascii
-.TP
-.B     300
-: Bell103 300 bps \-\-ascii
-.TP
-.B    rtty
-: RTTY 45.45 bps \-\-baudot \-\-stopbits 1.5
-.TP
-.B    same
-: SAME 520.83 bps \-\-startbits 0 \-\-stopbits 0 \-\-sync-byte 0xAB
-.br
-	NOAA Specific Area Message Encoding (SAME) protocol
 .SH EXAMPLES
 .TP
 .B minimodem --tx 100
diff --git a/src/minimodem.c b/src/minimodem.c
index 9e5699c..0d0232d 100644
--- a/src/minimodem.c
+++ b/src/minimodem.c
@@ -319,6 +319,7 @@ usage()
     "		     300       Bell103      300 bps --ascii\n"
     "		    rtty       RTTY       45.45 bps --baudot --stopbits=1.5\n"
     "		    same       NOAA SAME 520.83 bps --sync-byte=0xAB ...\n"
+    "		callerid       Bell202 CID 1200 bps\n"
     );
     exit(1);
 }
@@ -592,7 +593,12 @@ main( int argc, char*argv[] )
     databits_encoder	*bfsk_databits_encode;
     databits_decoder	*bfsk_databits_decode;
 
+    bfsk_databits_decode = databits_decode_ascii8;
+    bfsk_databits_encode = databits_encode_ascii8;
+
     if ( strncasecmp(modem_mode, "rtty",5)==0 ) {
+	bfsk_databits_decode = databits_decode_baudot;
+	bfsk_databits_encode = databits_encode_baudot;
 	bfsk_data_rate = 45.45;
 	if ( bfsk_n_data_bits == 0 )
 	    bfsk_n_data_bits = 5;
@@ -609,6 +615,14 @@ main( int argc, char*argv[] )
 	bfsk_mark_f = 2083.0 + 1/3.0;
 	bfsk_space_f = 1562.5;
 	band_width = bfsk_data_rate;
+    } else if ( strncasecmp(modem_mode, "caller",6)==0 ) {
+	if ( TX_mode ) {
+	    fprintf(stderr, "E: callerid --tx mode is not supported.\n");
+	    return 1;
+	}
+	bfsk_databits_decode = databits_decode_callerid;
+	bfsk_data_rate = 1200;
+	bfsk_n_data_bits = 8;
     } else {
 	bfsk_data_rate = atof(modem_mode);
 	if ( bfsk_n_data_bits == 0 )
@@ -617,15 +631,6 @@ main( int argc, char*argv[] )
     if ( bfsk_data_rate == 0.0 )
 	usage();
 
-    if ( bfsk_n_data_bits == 8 ) {
-	bfsk_databits_decode = databits_decode_ascii8;
-	bfsk_databits_encode = databits_encode_ascii8;
-    } else if ( bfsk_n_data_bits == 5 ) {
-	bfsk_databits_decode = databits_decode_baudot;
-	bfsk_databits_encode = databits_encode_baudot;
-    } else {
-	assert( 0 && bfsk_n_data_bits );
-    }
 
     if ( output_mode_binary )
 	bfsk_databits_decode = databits_decode_binary;
diff --git a/tests/test-70-callerid-mdmf b/tests/test-70-callerid-mdmf
new file mode 100755
index 0000000..e3da8b9
--- /dev/null
+++ b/tests/test-70-callerid-mdmf
@@ -0,0 +1,54 @@
+#!/bin/bash
+
+MINIMODEM="${MINIMODEM-./minimodem}"
+[ -f "$MINIMODEM" ] || {
+    MINIMODEM="../src/minimodem"
+    [ -f "$MINIMODEM" ] || {
+	echo "E: cannot find minimodem in ./ or ../src/" 1>&2
+	exit 1
+    }
+}
+
+
+bytesfile="testdata-callerid-mdmf.bytes"
+[ "$1" != "" ] && bytesfile="$1"
+
+
+TMPF="/tmp/minimodem-test-$$"
+trap "rm -f $TMPF.*" 0
+
+set -e
+
+textfile="${bytesfile%%.bytes}.txt"
+
+
+minimodem_tx_args="1200 --ascii"
+minimodem_rx_args="callerid"
+
+
+$MINIMODEM --tx --file $TMPF.wav $minimodem_tx_args < "$bytesfile"
+
+# cp $TMPF.wav /tmp/x.wav
+
+$MINIMODEM --rx --file $TMPF.wav $minimodem_rx_args \
+	> $TMPF.out 2> $TMPF.err || {
+    cat $TMPF.err
+    exit 1
+}
+
+cmp "$textfile" $TMPF.out
+
+{
+    read xlitcarrier
+    read xlitblankline
+    read xlithashes xlitnocarrier stats
+    stats="${stats% ###}"
+} < $TMPF.err
+
+
+result="OK     "
+exitcode=0
+
+echo -e "$result $stats"
+
+exit $exitcode
diff --git a/tests/test-71-callerid-sdmf b/tests/test-71-callerid-sdmf
new file mode 100755
index 0000000..4798466
--- /dev/null
+++ b/tests/test-71-callerid-sdmf
@@ -0,0 +1,2 @@
+#!/bin/bash
+exec ./test-70-callerid-mdmf testdata-callerid-sdmf.bytes
diff --git a/tests/testdata-callerid-mdmf.bytes b/tests/testdata-callerid-mdmf.bytes
new file mode 100644
index 0000000..d8265b0
--- /dev/null
+++ b/tests/testdata-callerid-mdmf.bytes
@@ -0,0 +1,2 @@
+€ 
03240902JOHN DOE
+8005551212}
\ No newline at end of file
diff --git a/tests/testdata-callerid-mdmf.txt b/tests/testdata-callerid-mdmf.txt
new file mode 100644
index 0000000..e283254
--- /dev/null
+++ b/tests/testdata-callerid-mdmf.txt
@@ -0,0 +1,4 @@
+CALLER-ID
+Time:  03/24 09:02
+Name:  JOHN DOE
+Phone: 800-555-1212
diff --git a/tests/testdata-callerid-sdmf.bytes b/tests/testdata-callerid-sdmf.bytes
new file mode 100644
index 0000000..82a1433
--- /dev/null
+++ b/tests/testdata-callerid-sdmf.bytes
@@ -0,0 +1 @@
+093012246095551212Q
\ No newline at end of file
diff --git a/tests/testdata-callerid-sdmf.txt b/tests/testdata-callerid-sdmf.txt
new file mode 100644
index 0000000..f5ba3ae
--- /dev/null
+++ b/tests/testdata-callerid-sdmf.txt
@@ -0,0 +1,3 @@
+CALLER-ID
+Time:  09/30 12:24
+Phone: 609-555-1212