[Com0com-cvs] com0com ReadMe.txt,1.8,1.9

[Vyacheslav F. <vf...@us...>]

Update of /cvsroot/com0com/com0com
In directory sc8-pr-cvs4.sourceforge.net:/tmp/cvs-serv11876

Modified Files:
	ReadMe.txt 
Log Message:
Added FAQ about receive buffer overrun


Index: ReadMe.txt
===================================================================
RCS file: /cvsroot/com0com/com0com/ReadMe.txt,v
retrieving revision 1.8
retrieving revision 1.9
diff -C2 -d -r1.8 -r1.9
*** ReadMe.txt	5 Dec 2005 10:43:19 -0000	1.8
--- ReadMe.txt	28 Jun 2006 13:59:03 -0000	1.9
***************
*** 9,13 ****
  Windows. You can create an unlimited number of virtual COM port
  pairs and use any pair to connect one application to another.
! Each COM port pair provides two COM ports with names starting
  at CNCA0 and CNCB0. The output to one port is the input from other
  port and vice versa.
--- 9,13 ----
  Windows. You can create an unlimited number of virtual COM port
  pairs and use any pair to connect one application to another.
! Each COM port pair provides two COM ports with default names starting
  at CNCA0 and CNCB0. The output to one port is the input from other
  port and vice versa.
***************
*** 111,112 ****
--- 111,127 ----
  A. You must prefix name with the special characters "\\.\". Try to open the port
     with CreateFile("\\\\.\\CNCA0", ...).
+ 
+ Q. My application hangs during its startup when it sends anything to one paired
+    COM port. The only way to unhang it is to start HyperTerminal, which is connected
+    to the other paired COM port. I didn't have this problem with physical serial
+    ports.
+ A. Your application can hang because receive buffer overrun is disabled by
+    default. You can fix the problem by enabling receive buffer overrun for the
+    receiving port. Also, to prevent some flow control issues you need to enable
+    baud rate emulation for the sending port. So, if your application use port CNCA0
+    and other paired port is CNCB0, then add the following to the registry:
+ 
+ [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\com0com\Parameters\CNCB0]
+ "EmuOverrun"=dword:FFFFFFFF
+ [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\com0com\Parameters\CNCA0]
+ "EmuBR"=dword:FFFFFFFF