diff --git a/modules/src/Action b/modules/src/Action
new file mode 100644
index 000000000..d30d0b021
--- /dev/null
+++ b/modules/src/Action
@@ -0,0 +1,39 @@
+name "system-call interface module"
+dir system
+end
+name "string routines module"
+dir string
+end
+name "formatted print module"
+dir print
+end
+name "assertion module"
+dir assert
+end
+name "memory allocation module"
+dir alloc
+end
+name "fast, wasting malloc"
+dir Xmalloc
+end
+name "fast, memory efficient malloc"
+dir malloc
+end
+name "EM messages generation module"
+dir em_mes
+end
+name "identifier table module"
+dir idf
+end
+name "input module"
+dir input
+end
+name "ACK-object reading and writing module"
+dir object
+end
+name "EM-code reading module"
+dir read_em
+end
+name "EM code generation module"
+dir em_code
+end
diff --git a/modules/src/Xmalloc/Makefile b/modules/src/Xmalloc/Makefile
new file mode 100644
index 000000000..de3288a94
--- /dev/null
+++ b/modules/src/Xmalloc/Makefile
@@ -0,0 +1,21 @@
+EMHOME=../../..
+HDIR = $(EMHOME)/modules/h
+INSTALL=$(EMHOME)/modules/install
+COMPARE=$(EMHOME)/modules/compare
+
+CFLAGS = -O -I$(HDIR)
+
+SOURCES =	Xmalloc.c
+
+OBJECTS =	Xmalloc.o
+
+all:		$(OBJECTS)
+
+install:	all
+		$(INSTALL) lib/Xmalloc.o
+
+compare:	all
+		$(COMPARE) lib/Xmalloc.o
+
+clean:
+		rm -f *.[oa]
diff --git a/modules/src/Xmalloc/Xmalloc.c b/modules/src/Xmalloc/Xmalloc.c
new file mode 100644
index 000000000..3320d1ce9
--- /dev/null
+++ b/modules/src/Xmalloc/Xmalloc.c
@@ -0,0 +1,142 @@
+/*	M E M O R Y  A L L O C A T I O N  R O U T I N E S	*/
+
+/*	The reason for having own memory allocation routines (malloc(),
+	realloc() and free()) is plain: the garbage collection performed by
+	the library functions malloc(), realloc() and free() costs a lot of
+	time, while in most cases (on a VAX) the freeing and reallocation of
+	memory is not necessary.
+	The (basic) memory allocating routines offered by this memory
+	handling package are:
+
+	char *malloc(n)		: allocate n bytes
+	char *realloc(ptr, n)	: reallocate buffer to n bytes
+					(works only if ptr was last allocated)
+	free(ptr)		: if ptr points to last allocated
+					memory, this memory is re-allocatable
+
+	This module imports routines from "system", an assertion macro,
+	and the compile-time
+	constants ALIGNBITS, ALLOCSIZ, DEBUG.
+	ALIGNBITS is an integer constant defining suitable alignment,
+	ALLOCSIZ is the size of the chunks of memory asked from the system,
+	DEBUG enables the assertions.
+*/
+
+#include	<assert.h>
+#include	<system.h>
+
+#ifndef ALIGNBITS
+#define ALIGNBITS	07
+#endif
+
+#ifndef ALLOCSIZ
+#define ALLOCSIZ	4096
+#endif
+
+/* the following variables are used for book-keeping */
+static int nfreebytes = 0;	/* # free bytes in sys_break-ed space */
+static char *freeb = 0;		/* pointer to first free byte */
+static char *lastalloc;		/* pointer to last malloced sp */
+static int lastnbytes;		/* nr of bytes in last allocated space */
+static char *firstfreeb;	/* pointer to first ever free byte */
+
+#define	ALIGN(m) (((m)&ALIGNBITS)? (m)+((1+ALIGNBITS)-((m)&ALIGNBITS)):(m))
+
+char *sys_break();
+
+char *
+malloc(n)
+	unsigned int n;
+{
+	/*	malloc() is a very simple malloc().
+	*/
+
+	n = ALIGN(n);
+	if (nfreebytes < n)	{
+		register int nbts = (n <= ALLOCSIZ) ? ALLOCSIZ : n;
+
+		if (!nfreebytes)	{
+			if (!firstfreeb) {
+				/* We arrive here the first time malloc is
+				   called
+				*/
+				int diff;
+
+				if (!(freeb = sys_break(0))) return 0;
+				if ((diff = (int)((long)freeb&ALIGNBITS))!=0) {
+					/* align memory to ALIGNBITS ... */
+					diff = (1 + ALIGNBITS) - diff;
+					if (!(freeb = sys_break(diff))) {
+					      return 0;
+					}
+					freeb += diff;
+					assert(((long)freeb & ALIGNBITS) == 0);
+				}
+				firstfreeb = freeb;
+			}
+			if (!(freeb = sys_break(nbts))) return 0;
+		}
+		else	{
+			if (!sys_break(nbts)) return 0;
+		}
+		nfreebytes += nbts;
+	}
+	lastalloc = freeb;
+	freeb = lastalloc + n;
+	lastnbytes = n;
+	nfreebytes -= n;
+	return lastalloc;
+}
+
+char *
+realloc(ptr, n)
+	char *ptr;
+	unsigned int n;
+{
+	/*	realloc() is designed to append more bytes to the latest
+		allocated piece of memory.
+	*/
+	register int nbytes = n;
+
+	if (!ptr || ptr != lastalloc) {	/* security */
+		return 0;
+	}
+	nbytes -= lastnbytes;		/* # bytes required */
+	if (nbytes == 0)	{	/* no extra bytes */
+		return lastalloc;
+	}
+
+	/*	if nbytes < 0: free last allocated bytes;
+		if nbytes > 0: allocate more bytes
+	*/
+	if (nbytes > 0) nbytes = ALIGN(nbytes);
+	if (nfreebytes < nbytes)	{
+		register int nbts = (nbytes < ALLOCSIZ) ? ALLOCSIZ : nbytes;
+		if (!sys_break(nbts)) return 0;
+		nfreebytes += nbts;
+	}
+	freeb += nbytes;	/* less bytes */
+	lastnbytes += nbytes;	/* change nr of last all. bytes */
+	nfreebytes -= nbytes;	/* less or more free bytes */
+	return lastalloc;
+}
+
+free(p)
+	char *p;
+{
+	if (lastalloc && lastalloc == p) {
+		nfreebytes += lastnbytes;
+		freeb = lastalloc;
+		lastnbytes = 0;
+		lastalloc = 0;
+	}
+}
+
+#ifdef	DEBUG
+mem_stat()
+{
+
+	printf("Total nr of bytes allocated: %d\n",
+		sys_break(0) - firstfreeb);
+}
+#endif	DEBUG