diff --git a/pointprocesses/code/rasterplot.m b/pointprocesses/code/rasterplot.m
index ccbfe60..beb1970 100644
--- a/pointprocesses/code/rasterplot.m
+++ b/pointprocesses/code/rasterplot.m
@@ -6,16 +6,12 @@ function rasterplot(spikes, tmax)
 % Arguments:
 %   spikes: a cell array of vectors of spike times in seconds
 %   tmax: plot spike raster up to tmax seconds
-    in_msecs = tmax < 1.5
     spiketimes = [];
     trials = [];
     ntrials = length(spikes);
     for k = 1:ntrials
         times = spikes{k};
         times = times(times<tmax);
-        if in_msecs
-            times = 1000.0*times;               % conversion to ms
-        end
         % (x,y) pairs for start and stop of stroke
         % plus nan separating strokes:
         spiketimes = [spiketimes, ...
@@ -30,13 +26,8 @@ function rasterplot(spikes, tmax)
     trials = trials(:);
     % plotting this is lightning fast:
     plot(spiketimes, trials, 'k')
-    if in_msecs
-        xlabel('Time [ms]');
-        xlim([0.0 1000.0*tmax]);
-    else
-        xlabel('Time [s]');
-        xlim([0.0 tmax]);
-    end
+    xlabel('Time [s]');
+    xlim([0.0 tmax]);
     ylabel('Trials');
     ylim([0.3 ntrials+0.7]);
 end
diff --git a/pointprocesses/code/lifadapt.mat b/pointprocesses/exercises/lifadapt.mat
similarity index 100%
rename from pointprocesses/code/lifadapt.mat
rename to pointprocesses/exercises/lifadapt.mat
diff --git a/pointprocesses/code/pifou.mat b/pointprocesses/exercises/pifou.mat
similarity index 100%
rename from pointprocesses/code/pifou.mat
rename to pointprocesses/exercises/pifou.mat
diff --git a/pointprocesses/exercises/pointprocesses-1.tex b/pointprocesses/exercises/pointprocesses-1.tex
index eed6a5a..2da20f9 100644
--- a/pointprocesses/exercises/pointprocesses-1.tex
+++ b/pointprocesses/exercises/pointprocesses-1.tex
@@ -55,7 +55,7 @@
     \end{solution}
 
     \newsolutionpage    
-    \part Write a function that illustrated the spike times of the
+    \part Write a function that displays the spike times of the
     first $t_{max}$ seconds in a raster plot. Each spike train is one
     row in the raster plot. Each spike is a vertical line at the time
     of the spike. When appropriate, the function should use milliseconds 
diff --git a/pointprocesses/code/poisson.mat b/pointprocesses/exercises/poisson.mat
similarity index 100%
rename from pointprocesses/code/poisson.mat
rename to pointprocesses/exercises/poisson.mat