diff --git a/a.out b/chap0/a.out
similarity index 52%
rename from a.out
rename to chap0/a.out
index aa91c57..bfe2420 100755
Binary files a/a.out and b/chap0/a.out differ
diff --git a/mem.c b/chap0/mem.c
similarity index 100%
rename from mem.c
rename to chap0/mem.c
diff --git a/chap0/parent.c b/chap0/parent.c
new file mode 100644
index 0000000..aed337c
--- /dev/null
+++ b/chap0/parent.c
@@ -0,0 +1,16 @@
+#include <stdio.h> // p r i n t f
+#include <stdlib.h> // e x i t ( . . ) , EXIT_SUCCESS
+#include <unistd.h> // f o r k ( ) , getpid ( )
+
+
+int main ( int argc , char * argv []) {
+       	pid_t fvalue = fork ();
+       	if ( fvalue != 0) {
+	       	// Parent process
+		printf("[%ld] I am your father , %ld!\n " , getpid () , fvalue );
+       	} else {
+	       	// Child process
+		printf("[%ld] Nooooooooooooooo ! (%ld)\n " , getpid () , fvalue );
+       	}
+       	exit ( EXIT_SUCCESS );
+}
diff --git a/sig.c b/chap0/sig.c
similarity index 100%
rename from sig.c
rename to chap0/sig.c
diff --git a/chap1/a.out b/chap1/a.out
new file mode 100755
index 0000000..0ba1161
Binary files /dev/null and b/chap1/a.out differ
diff --git a/chap1/application-sigrt.h b/chap1/application-sigrt.h
new file mode 100644
index 0000000..5bdeff7
--- /dev/null
+++ b/chap1/application-sigrt.h
@@ -0,0 +1,9 @@
+#ifndef __HAVE_APPLICATION_SIGRT__
+#define __HAVE_APPLICATION_SIGRT__
+
+# include <signal.h> // SIGRTMIN
+
+# define SIGRT_START (SIGRTMIN +1)
+# define SIGRT_FINAL ( SIGRTMIN +0)
+
+# endif // __HAVE_APPLICATION_SIGRT__
diff --git a/chap1/application-sigrt.h.gch b/chap1/application-sigrt.h.gch
new file mode 100644
index 0000000..cae6dfc
Binary files /dev/null and b/chap1/application-sigrt.h.gch differ
diff --git a/chap1/canvas.c b/chap1/canvas.c
new file mode 100644
index 0000000..6e87987
--- /dev/null
+++ b/chap1/canvas.c
@@ -0,0 +1,50 @@
+#include <stdlib.h> // e x i t ( . . ) , EXIT_SUCCESS
+#include "application-sigrt.h"
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+
+#define  __START__ 0
+#define EXPECTING 1
+#define OPERATING 2
+#define __FINAL__ 3
+
+sigset_t mask ;
+volatile sig_atomic_t state = __START__ ;
+
+void handleStart ( int signum , siginfo_t * info , void * context ) {
+	state = OPERATING ;
+	sigaddset (& mask , SIGRT_START );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+}
+
+void handleFinal ( int signum , siginfo_t * info , void * context ) {
+	state = __FINAL__ ;
+	sigaddset (& mask , SIGRT_FINAL );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+}
+
+int main ( int argc , char * argv []) {
+	sigfillset (& mask );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+	struct sigaction descriptor ;
+	memset(& descriptor , 0 , sizeof ( descriptor ));
+	descriptor.sa_flags = SA_SIGINFO ;
+	descriptor.sa_sigaction = handleStart ;
+	sigaction ( SIGRT_START , & descriptor , NULL );
+	descriptor.sa_sigaction = handleFinal ;
+	sigaction ( SIGRT_FINAL , & descriptor , NULL );
+	state = EXPECTING ;
+	sigdelset (& mask , SIGRT_START );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+	while ( state == EXPECTING )
+		pause();
+	sigdelset (& mask , SIGRT_FINAL );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+	while ( state == OPERATING ) {
+		// Working on something . . .
+		printf("f");
+	}
+	exit ( EXIT_SUCCESS );
+}
diff --git a/chap1/ex1.c b/chap1/ex1.c
new file mode 100644
index 0000000..0de8ef8
--- /dev/null
+++ b/chap1/ex1.c
@@ -0,0 +1,58 @@
+#include <stdlib.h> // e x i t ( . . ) , EXIT_SUCCESS
+#include "application-sigrt.h"
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+
+#define  __START__ 0
+#define EXPECTING 1
+#define OPERATING 2
+#define __FINAL__ 3
+
+sigset_t mask ;
+volatile sig_atomic_t state = __START__ ;
+
+void handleStart ( int signum , siginfo_t * info , void * context ) {
+	state = OPERATING ;
+	sigaddset (& mask , SIGRT_START );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+}
+
+void handleFinal ( int signum , siginfo_t * info , void * context ) {
+	state = __FINAL__ ;
+	sigaddset (& mask , SIGRT_FINAL );
+	sigprocmask ( SIG_SETMASK , & mask , NULL );
+}
+
+int main ( int argc , char * argv []) {
+	pid_t fvalue = fork();
+	
+	if (fvalue != 0){
+		sigfillset (& mask );
+		sigprocmask ( SIG_SETMASK , & mask , NULL );
+		struct sigaction descriptor ;
+		memset(& descriptor , 0 , sizeof ( descriptor ));
+		descriptor.sa_flags = SA_SIGINFO ;
+		descriptor.sa_sigaction = handleStart ;
+		sigaction ( SIGRT_START , & descriptor , NULL );
+		descriptor.sa_sigaction = handleFinal ;
+		sigaction ( SIGRT_FINAL , & descriptor , NULL );
+		state = EXPECTING ;
+		sigdelset (& mask , SIGRT_START );
+		sigprocmask ( SIG_SETMASK , & mask , NULL );
+		while ( state == EXPECTING )
+			pause();
+		sigdelset (& mask , SIGRT_FINAL );
+		sigprocmask ( SIG_SETMASK , & mask , NULL );
+		while ( state == OPERATING ) {
+			// Working on something . . .
+			printf("f");
+		}
+	} else {
+
+	}
+
+	
+	exit ( EXIT_SUCCESS );
+}
diff --git a/chap1/modif.txt b/chap1/modif.txt
new file mode 100644
index 0000000..5dfa9d7
--- /dev/null
+++ b/chap1/modif.txt
@@ -0,0 +1,3 @@
+requested.tv_nsec = 45e7
+pas usec
+vasue = value