--- a/src/README.txt
+++ b/src/README.txt
@@ -8,8 +8,8 @@ You might also want to read ":help devel
 
 JUMPING AROUND
 
-First of all, use ":make tags" to generate a tags file, so that you can use
-the ":tag" command to jump around the source code.
+First of all, use ":make tags" to generate a tags file, so that you can jump
+around in the source code.
 
 To jump to a function or variable definition, move the cursor on the name and
 use the CTRL-] command.  Use CTRL-T or CTRL-O to jump back.
@@ -43,6 +43,21 @@ Most code can be found in a file with an
 	window.c	handling split windows
 
 
+DEBUGGING
+
+If you have a reasonable recent version of gdb, you can use the :Termdebug
+command to debug Vim.  See  ":help :Termdebug".
+
+When something is time critical or stepping through code is a hassle, use the
+channel logging to create a time-stamped log file.  Add lines to the code like
+this:
+	ch_log(NULL, "Value is now %02x", value);
+After compiling and starting Vim, do:
+	:call ch_logfile('debuglog', 'w')
+And edit "debuglog" to see what happens.  The channel functions already have
+ch_log() calls, thus you always see that in the log.
+
+
 IMPORTANT VARIABLES
 
 The current mode is stored in "State".  The values it can have are NORMAL,