2 files changed, 25 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 9745e5f7..7da494e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2014-07-02  Kaz Kylheku  <kaz@kylheku.com>
 
+	* txr.1: Documented usleep.
+
+2014-07-02  Kaz Kylheku  <kaz@kylheku.com>
+
 	* eval.c (dwim_loc): Support indexing using a list of positions,
 	such as obtained by the where function.
 
diff --git a/txr.1 b/txr.1
index 53557fa6..801c5f5f 100644
--- a/txr.1
+++ b/txr.1
@@ -13828,6 +13828,27 @@ EXIT_FAILURE, and t corresponds to EXIT_SUCCESS. These are platform-independent
 indicators of failed or successful termination. The numeric value 0 also
 indicates success.
 
+.SS Function usleep
+
+.TP
+Syntax:
+
+  (usleep <usec>)
+
+.TP
+Description:
+
+The usleep function suspends the execution of the program for at least
+<usec> microseconds.
+
+The return value is t if the sleep was successfully executed. A nil
+value indicates premature wakup or complete failure.
+
+Note: the actual sleep resolution is not guaranteed, and depends on granularity
+of the system timer.  Actual sleep times may be rounded up to the nearest 10
+millisecond multiple on a system where timed suspensions are triggered by a 100
+Hz tick.
+
 .SS Function mkdir
 
 .TP