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diff --git a/doc/threads.texi b/doc/threads.texi
index c1519e8..d90b438 100644
--- a/doc/threads.texi
+++ b/doc/threads.texi
@@ -240,6 +240,22 @@ serial drivers.
 Interrupt queue, for managing a circular queue that both kernel
 threads and interrupt handlers want to access.  Used by the keyboard
 and serial drivers.
+
+@item rtc.c
+@itemx rtc.h
+Real-time clock driver, to enable the kernel to determine the current
+date and time.  By default, this is only used by @file{thread/init.c}
+to choose an initial seed for the random number generator.
+
+@item speaker.c
+@itemx speaker.h
+Driver that can produce tones on the PC speaker.
+
+@item pit.c
+@itemx pit.h
+Code to configure the 8254 Programmable Interrupt Timer.  This code is
+used by both @file{devices/timer.c} and @file{devices/speaker.c}
+because each device uses one of the PIT's output channel.
 @end table
 
 @node lib files
@@ -277,7 +293,11 @@ more information.
 
 @item random.c
 @itemx random.h
-Pseudo-random number generator.
+Pseudo-random number generator.  The actual sequence of random values
+will not vary from one Pintos run to another, unless you do one of
+three things: specify a new random seed value on the @option{-rs}
+kernel command-line option on each run, or use a simulator other than
+Bochs, or specify the @option{-r} option to @command{pintos}.
 
 @item round.h
 Macros for rounding.
@@ -364,13 +384,7 @@ with each other, requiring lots of last-minute debugging.  Some groups
 who have done this have turned in code that did not even compile or
 boot, much less pass any tests.
 
-Instead, we recommend integrating your team's changes early and often,
-using a source code control system such as CVS (@pxref{CVS}) or a
-group collaboration site such as SourceForge (@pxref{SourceForge}).
-This is less likely to produce surprises, because everyone can see
-everyone else's code as it is written, instead of just when it is
-finished.  These systems also make it possible to review changes and,
-when a change introduces a bug, drop back to working versions of code.
+@localcvspolicy{}
 
 You should expect to run into bugs that you simply don't understand
 while working on this and subsequent projects.  When you do,
@@ -480,9 +494,9 @@ priority.  If necessary, you may impose a reasonable limit on depth of
 nested priority donation, such as 8 levels.
 
 You must implement priority donation for locks.  You need not
-implement priority donation for semaphores or condition variables
-(but you are welcome to do so).  You do need to implement
-priority scheduling in all cases.
+implement priority donation for the other Pintos synchronization
+constructs.  You do need to implement priority scheduling in all
+cases.
 
 Finally, implement the following functions that allow a thread to
 examine and modify its own priority.  Skeletons for these functions are
@@ -696,7 +710,7 @@ kernel thread but the first.
 Don't worry about the possibility of timer values overflowing.  Timer
 values are expressed as signed 64-bit numbers, which at 100 ticks per
 second should be good for almost 2,924,712,087 years.  By then, we
-expect Pintos to have been phased out of the CS 140 curriculum.
+expect Pintos to have been phased out of the @value{coursenumber} curriculum.
 @end table
 
 @node Priority Scheduling FAQ
@@ -766,6 +780,36 @@ becomes the higher of the newly set priority or the highest donated
 priority.  When the donations are released, the thread's priority
 becomes the one set through the function call.  This behavior is checked
 by the @code{priority-donate-lower} test.
+
+@item Doubled test names in output make them fail.
+
+Suppose you are seeing output in which some test names are doubled,
+like this:
+
+@example
+(alarm-priority) begin
+(alarm-priority) (alarm-priority) Thread priority 30 woke up.
+Thread priority 29 woke up.
+(alarm-priority) Thread priority 28 woke up.
+@end example
+
+What is happening is that output from two threads is being
+interleaved.  That is, one thread is printing @code{"(alarm-priority)
+Thread priority 29 woke up.\n"} and another thread is printing
+@code{"(alarm-priority) Thread priority 30 woke up.\n"}, but the first
+thread is being preempted by the second in the middle of its output.
+
+This problem indicates a bug in your priority scheduler.  After all, a
+thread with priority 29 should not be able to run while a thread with
+priority 30 has work to do.
+
+Normally, the implementation of the @code{printf()} function in the
+Pintos kernel attempts to prevent such interleaved output by acquiring
+a console lock during the duration of the @code{printf} call and
+releasing it afterwards.  However, the output of the test name,
+e.g., @code{(alarm-priority)}, and the message following it is output
+using two calls to @code{printf}, resulting in the console lock being
+acquired and released twice.
 @end table
 
 @node Advanced Scheduler FAQ