diff --git a/Modules/.gitignore b/Modules/.gitignore
index d1eaedc..1acb676 100644
--- a/Modules/.gitignore
+++ b/Modules/.gitignore
@@ -3,6 +3,7 @@ chkpixels
 twavm
 trnd
 t_centermag
+demo_spitpgm
 
 datas/
 
diff --git a/Modules/Makefile b/Modules/Makefile
index f320092..6acdde0 100644
--- a/Modules/Makefile
+++ b/Modules/Makefile
@@ -65,3 +65,6 @@ trnd:		trnd.f90 Makefile libtth90modules.a
 twavm:		twavm.f90 Makefile libtth90modules.a
 	gfortran $(GFOPT) $<  libtth90modules.a -o $@
 
+demo_spitpgm:	demo_spitpgm.f90 Makefile libtth90modules.a
+	gfortran $(GFOPT) $<  libtth90modules.a -o $@
+
diff --git a/Modules/README.md b/Modules/README.md
index e82a2a6..29221ce 100644
--- a/Modules/README.md
+++ b/Modules/README.md
@@ -11,7 +11,8 @@ This is just a [WIP](./wavmetrics.f90), see [twavm](./twavm.f90) for a no-use ca
 
 ### spitpgm
 
-Write gray level 2d buffer (aka picture) to disk in the NetPNM format.
+Some procedures to [write gray level](./SpitPGM.md) 2d buffer of integer
+(aka picture) to disk in the *ascii* NetPNM format. 
 
 ### pixrgb
 
diff --git a/Modules/SpitPGM.md b/Modules/SpitPGM.md
new file mode 100644
index 0000000..76b47ee
--- /dev/null
+++ b/Modules/SpitPGM.md
@@ -0,0 +1,21 @@
+# SpitPGM
+
+What is a `.pgm` file ? And what we can do with this module ?
+
+You have a bi-dimensionnal array of integer and you want show those
+fancy datas as a fancy picture ? So we have a few funcs for doing
+that..
+
+```
+subroutine spit_as_pgm_16(pic, fname)
+    integer, intent(in), dimension (:,:)  ::  pic
+    character (len=*), intent(in)         ::  fname
+```
+
+and
+
+```
+subroutine spit_as_pgm_16(pic, fname)
+    integer, intent(in), dimension (:,:)  ::  pic
+    character (len=*), intent(in)         ::  fname
+```
diff --git a/Modules/demo_spitpgm.f90 b/Modules/demo_spitpgm.f90
new file mode 100644
index 0000000..bac588a
--- /dev/null
+++ b/Modules/demo_spitpgm.f90
@@ -0,0 +1,18 @@
+program demo_spitpgm
+  use spitpgm
+
+  integer      :: fancydatas(128, 128)
+  integer      :: i, j
+
+  fancydatas = 0
+
+  do i=1, 128
+    do j=1, 128
+    fancydatas(i,j) = mod(i*j, 65000)
+    enddo
+  enddo
+
+  call spit_as_pgm_16(fancydatas, 'fancydatas.pgm')
+
+end program
+
diff --git a/Modules/trnd.f90 b/Modules/trnd.f90
index b049dc9..736c78e 100644
--- a/Modules/trnd.f90
+++ b/Modules/trnd.f90
@@ -8,7 +8,7 @@ program essai
 
   ! integer                     :: foo, bar
 
-  write(0, *)   "----------------- essai -------------------"
+  write(0, *)   "------------ essai random -------------"
 
   call init_random_seed()           ! in module 'mathstuff'
   ! call test_noisepictures_rgb()