Add parity

README

@@ -14,12 +14,12 @@
 
 	app_softmodem.c depends on the spandsp library
 	(http://www.soft-switch.org/).
-	
+
 	It is tested and working with Asterisk 13t.
-	
+
 	To compile put app_softmodem.c in the apps/ dir of your Asterisk source.
 	Compile with 'make apps'.
-	
+
 	To use do a 'make install' on your asterisk source or copy
 	apps/app_softmodem.so into your asterisk module directory
 	(/lib/asterisk/mosules).
@@ -31,10 +31,10 @@
 	exten => btx,1,Answer()
 	exten => btx,n,Softmodem(host, port, options)
 	exten => btx,n,Hangup()
-	
+
 	Without any arguments the application acts as a V.23 modem and connects to a
 	Telnet server (port 23) on localhost.
-	
+
 	Options are:
 		r(...): rx cutoff (dBi, float, default: -35)
 		t(...): tx power (dBi, float, default: -28)
@@ -47,13 +47,20 @@
 		l or m: least or most significant bit first (default: m)
 		d(...): amount of data bits (5-8, default: 8)
 		s(...): amount of stop bits (1-2, default: 1)
+		e or o: add even or odd parity bit
 		u:      Send Ulm Relay Protocol header to Telnet server
 		n:      Send NULL-Byte to modem after carrier detection (Btx specific)
-	
+
 	To act as a "Btx Vermittlungsstelle" (German videotex system) using V.23, 8 data bits, 1 stop bit and sending a NULL byte upon carrier detection and connecting to a "twistedUlm" server on port 8289 (thus sending the ULM header):
-	
+
 	exten => 190,1,Softmodem(localhost, 8289, v(V23)ld(8)s(1)un)
-
+
+	To accept calls fom UK Prestel terminals, using V.23, 7 data bits, Even parity, 1 stop bit -
+
+	exten => 618,n,Softmodem(localhost, 6502, v(V23),ld(7)es(1)t(-8))
+
+
+
 	The modem seems to work fine with VOIP as long as you use a codec like G.711
 	(alaw/ulaw). Please deactivate any echo cancellation you might use.
 
@@ -62,32 +69,32 @@
  Btx, the Ulm Relay Protocol, general description of operation
 -------------------------------------------------------------------------------
 
-	After the softmodem picks up the line a TCP connection to the specified host 
+	After the softmodem picks up the line a TCP connection to the specified host
 	and port is established, the call is dropped when this wasn't successfull.
-	
+
 	When the "n" option is specified a NULL byte is send to the caller upon the detection of a carrier signal from the caller. The Btx system in Germany did this to request the caller's identification.
-	
+
 	With the "u" option specified a header is send to the TCP server at this
 	point. The header consists of some "name: value" pairs, separated by a CR+LF newline, terminated	by a double newline.
-	
+
 	At the moment this header looks like (for V.23):
 		Version: 1
 		TXspeed: 120
 		RXspeed: 7.5
 	Speeds are in bytes-per-second and may be used by the server to estimate
 	the length of the transmission.
-	
+
 	After the header all data received from the terminal is put onto the socket
 	and all data received from the socket is put on the line.
-	
+
 	The line is hung up when the server drops the connection, just as the
 	connection to the server is dropped when the line is hung up.
-	
+
 	You find my "Ulm Relay Protocol" server here:
 	http://github.com/proquar/twistedUlm
 	It sends CEPT T/CD 6-1 encoded data, which it retrieves from a webserver,
 	to the terminal and provides the characteristic BTX look-and-feel.
-	
+
 	You may also be interested in:
 		http://runningserver.com/?page=runningserver.content.thelab.bildschirmtrix
 	And you find a description of BTX MarkupLanguage here:
@@ -98,7 +105,7 @@
 -------------------------------------------------------------------------------
 
 	Christian Groeger <code@proquari.at>
-	
+
 	Based on code by:
 	Dmitry Andrianov <asterisk@dima.spb.ru>
 	Steve Underwood <steveu@coppice.org>
@@ -783,4 +790,4 @@ into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.