diff --git a/Modules/.gitignore b/Modules/.gitignore
index 4aafacb..4d3cb06 100644
--- a/Modules/.gitignore
+++ b/Modules/.gitignore
@@ -1,5 +1,7 @@
 
 chkpixels
+t
+trnd
 
 *.pgm
 *.pnm
diff --git a/Modules/Makefile b/Modules/Makefile
index 06c4cac..0923f72 100644
--- a/Modules/Makefile
+++ b/Modules/Makefile
@@ -1,29 +1,44 @@
 #
-#		* Fortraneries *
+#		* Fortraneries from tTh *
 #
 #	Makefile for the general purpose moduls
 #
 
-GFOPT  =  -Wall  -Wextra  -time  -g
+GFOPT  =  -Wall -Wextra -g -I.
 
-all:	chkpixels
+all:	chkpixels t
 
 # -----------------------------------------------
 
 spitpgm.o:		spitpgm.f90 Makefile
-	gfortran $(GFOPT) -c $< -o $@
+	gfortran $(GFOPT) -c $<
 
 pixrgb.o:		pixrgb.f90 Makefile
-	gfortran $(GFOPT) -c $< -o $@
+	gfortran $(GFOPT) -c $<
+
+centermag.o:		centermag.f90 Makefile
+	gfortran $(GFOPT) -c $<
+
+dummy.o:		dummy.f90 Makefile
+	gfortran $(GFOPT) -c $<
 
 trials.o:		trials.f90 Makefile
-	gfortran $(GFOPT) -c $< -o $@
+	gfortran $(GFOPT) -c $<
+
+mathstuff2.o:	mathstuff2.f90 Makefile
+	gfortran $(GFOPT) -c $<
 
 #
 #     programmes de testouille
 #
-OBJS = trials.o spitpgm.o pixrgb.o
+OBJS =	trials.o spitpgm.o pixrgb.o centermag.o dummy.o	\
+	mathstuff2.o
 
 chkpixels:	chkpixels.f90 Makefile $(OBJS)
 	gfortran $(GFOPT) $<  $(OBJS) -o $@
 
+t:		t.f90 Makefile $(OBJS)
+	gfortran $(GFOPT) $<  $(OBJS) -o $@
+
+trnd:		trnd.f90 Makefile $(OBJS)
+	gfortran $(GFOPT) $<  $(OBJS) -o $@
diff --git a/Modules/README.md b/Modules/README.md
index 4ee7f64..5d37577 100644
--- a/Modules/README.md
+++ b/Modules/README.md
@@ -1,14 +1,29 @@
 # General purpose modules
 
+## Compiler un module
 
-## spitpgm
+Mmmmm...
+
+## Modules disponibles
+
+
+### spitpgm
 
 Write gray level 2d buffer (aka picture) to disk in the NetPNM format.
 
-## pixrgb
+### pixrgb
 
 Write 8 bits RGB pictures to PNM format.
 
-## trials
+### trials
 
 Experimental WIPs from hell.
+
+### dummy
+
+A "do nothing" useless module. But you cas use it to fool an optimizing
+compiler, or have a sane place to put a breakpoint with gdb
+
+## TODO
+
+- écrire la doc !
diff --git a/Modules/t.f90 b/Modules/t.f90
new file mode 100644
index 0000000..e2d520d
--- /dev/null
+++ b/Modules/t.f90
@@ -0,0 +1,35 @@
+program t
+
+  use      centermag
+  implicit none
+
+  type(t_centermag)      :: cmag
+
+  print *, '====== programme de test ======'
+
+  cmag%wscr = 800
+  cmag%hscr = 600
+
+  call essai_centermag(cmag)
+  print *
+
+  STOP ': PAF LE CHIEN ?'
+
+!       --------------
+contains
+!       --------------
+subroutine essai_centermag(cm)
+    type(t_centermag), intent(in)   :: cm
+
+    real                            :: rx, ry
+
+    call  print_centermag (cm)
+    print *
+
+    call  centermag_scr2real(1, 1, rx, ry)
+    print *, 'to real  :', rx, ry
+
+end subroutine
+!       --------------
+
+end program
diff --git a/Modules/trnd.f90 b/Modules/trnd.f90
new file mode 100644
index 0000000..a520c3e
--- /dev/null
+++ b/Modules/trnd.f90
@@ -0,0 +1,21 @@
+program essai
+
+  use mathstuff2
+  implicit none
+
+  integer                     :: foo, bar
+  real                        :: quux
+  double precision            :: somme
+
+  write(0, *)   "----------------- essai -------------------"
+
+  call init_random_seed()           ! in module 'mathstuff'
+  somme = 0.0
+  do foo=1, 500
+    quux = rand() + rand()
+    somme = somme + quux
+    bar = mod(irand(), 7)
+    print *, foo, quux, somme/foo, bar
+  enddo
+
+end program