diff --git a/Makefile b/Makefile
index fb7b0eb..7107a45 100644
--- a/Makefile
+++ b/Makefile
@@ -52,6 +52,7 @@ dist:
 		$(PACKAGE)-$(VERSION)/src/arch/i386.c \
 		$(PACKAGE)-$(VERSION)/src/arch/i386_real.c \
 		$(PACKAGE)-$(VERSION)/src/arch/i486.c \
+		$(PACKAGE)-$(VERSION)/src/arch/i586.c \
 		$(PACKAGE)-$(VERSION)/src/arch/i686.c \
 		$(PACKAGE)-$(VERSION)/src/arch/sparc.c \
 		$(PACKAGE)-$(VERSION)/src/arch/Makefile \
@@ -60,6 +61,7 @@ dist:
 		$(PACKAGE)-$(VERSION)/src/arch/i386.ins \
 		$(PACKAGE)-$(VERSION)/src/arch/i386.reg \
 		$(PACKAGE)-$(VERSION)/src/arch/i486.ins \
+		$(PACKAGE)-$(VERSION)/src/arch/i586.ins \
 		$(PACKAGE)-$(VERSION)/src/arch/i686.ins \
 		$(PACKAGE)-$(VERSION)/src/arch/i686.reg \
 		$(PACKAGE)-$(VERSION)/src/arch/null.ins \
@@ -76,6 +78,7 @@ dist:
 		$(PACKAGE)-$(VERSION)/test/i386.S \
 		$(PACKAGE)-$(VERSION)/test/i386_real.S \
 		$(PACKAGE)-$(VERSION)/test/i486.S \
+		$(PACKAGE)-$(VERSION)/test/i586.S \
 		$(PACKAGE)-$(VERSION)/test/i686.S \
 		$(PACKAGE)-$(VERSION)/test/sparc.S \
 		$(PACKAGE)-$(VERSION)/test/Makefile \
diff --git a/src/arch/Makefile b/src/arch/Makefile
index 6e36e1c..ae43986 100644
--- a/src/arch/Makefile
+++ b/src/arch/Makefile
@@ -1,4 +1,4 @@
-TARGETS	= i386.so i386_real.so i486.so i686.so sparc.so
+TARGETS	= i386.so i386_real.so i486.so i586.so i686.so sparc.so
 PREFIX	= /usr/local
 DESTDIR	= 
 LIBDIR	= $(PREFIX)/lib
@@ -39,6 +39,13 @@ i486_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 i486.so: $(i486_OBJS)
 	$(LD) -o i486.so $(i486_OBJS) $(i486_LDFLAGS)
 
+i586_OBJS = i586.o
+i586_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
+i586_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
+
+i586.so: $(i586_OBJS)
+	$(LD) -o i586.so $(i586_OBJS) $(i586_LDFLAGS)
+
 i686_OBJS = i686.o
 i686_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 i686_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
@@ -62,6 +69,9 @@ i386_real.o: i386_real.c common.ins null.ins i386.h i386.ins i386.reg
 i486.o: i486.c common.ins null.ins i386.h i386.ins i386.reg i486.ins
 	$(CC) $(i486_CFLAGS) -c i486.c
 
+i586.o: i586.c common.ins null.ins i386.h i386.ins i386.reg i486.ins i586.ins
+	$(CC) $(i586_CFLAGS) -c i586.c
+
 i686.o: i686.c common.ins null.ins i386.h i386.ins i386.reg i486.ins i686.reg
 	$(CC) $(i686_CFLAGS) -c i686.c
 
@@ -69,7 +79,7 @@ sparc.o: sparc.c common.ins null.ins sparc.ins sparc.reg
 	$(CC) $(sparc_CFLAGS) -c sparc.c
 
 clean:
-	$(RM) -- $(i386_OBJS) $(i386_real_OBJS) $(i486_OBJS) $(i686_OBJS) $(sparc_OBJS)
+	$(RM) -- $(i386_OBJS) $(i386_real_OBJS) $(i486_OBJS) $(i586_OBJS) $(i686_OBJS) $(sparc_OBJS)
 
 distclean: clean
 	$(RM) -- $(TARGETS)
@@ -82,6 +92,8 @@ install: $(TARGETS)
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/asm/arch
 	$(INSTALL) -m 0644 -- i486.so $(DESTDIR)$(LIBDIR)/asm/arch/i486.so
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/asm/arch
+	$(INSTALL) -m 0644 -- i586.so $(DESTDIR)$(LIBDIR)/asm/arch/i586.so
+	$(MKDIR) $(DESTDIR)$(LIBDIR)/asm/arch
 	$(INSTALL) -m 0644 -- i686.so $(DESTDIR)$(LIBDIR)/asm/arch/i686.so
 	$(MKDIR) $(DESTDIR)$(LIBDIR)/asm/arch
 	$(INSTALL) -m 0644 -- sparc.so $(DESTDIR)$(LIBDIR)/asm/arch/sparc.so
@@ -90,6 +102,7 @@ uninstall:
 	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/i386.so
 	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/i386_real.so
 	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/i486.so
+	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/i586.so
 	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/i686.so
 	$(RM) -- $(DESTDIR)$(LIBDIR)/asm/arch/sparc.so
 
diff --git a/src/arch/i386.ins b/src/arch/i386.ins
index 4b64a5d..cf29bf4 100644
--- a/src/arch/i386.ins
+++ b/src/arch/i386.ins
@@ -419,6 +419,8 @@
 { "fwait",	0x9b,		OP1F, AOT_NONE,   AOT_NONE,  AOT_NONE	},
 /* NOP		0x90		1					*/
 { "nop",	0x90,		OP1F, AOT_NONE,   AOT_NONE,  AOT_NONE	},
+/* REP									*/
+/* FIXME implement */
 /* RET		0xc2		1     imm16				*/
 { "ret",	0xc2,		OP1F, OP_U16,     AOT_NONE,  AOT_NONE	},
 /* RET		0xca		1     imm16				*/
diff --git a/src/arch/i586.c b/src/arch/i586.c
new file mode 100644
index 0000000..d4b8667
--- /dev/null
+++ b/src/arch/i586.c
@@ -0,0 +1,80 @@
+/* $Id$ */
+/* Copyright (c) 2011 Pierre Pronchery <khorben@defora.org> */
+/* This file is part of DeforaOS Devel asm */
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+
+
+#include <stddef.h>
+#include <string.h>
+#include "Asm.h"
+
+
+/* i586 */
+/* private */
+/* types */
+/* register sizes */
+#define REG(name, size, id) REG_ ## name ## _size = size,
+enum
+{
+#include "i386.reg"
+	REG_size_count
+};
+#undef REG
+
+/* register ids */
+#define REG(name, size, id) REG_ ## name ## _id = id,
+enum
+{
+#include "i386.reg"
+	REG_id_count
+};
+#undef REG
+
+
+/* variables */
+#define REG(name, size, id) { "" # name, size, id },
+static ArchRegister _i586_registers[] =
+{
+#include "i386.reg"
+	{ NULL,		0, 0 }
+};
+#undef REG
+
+static ArchInstruction _i586_instructions[] =
+{
+#include "i386.ins"
+#include "i486.ins"
+#include "i586.ins"
+#include "common.ins"
+#include "null.ins"
+};
+
+
+/* functions */
+#include "i386.h"
+
+
+/* public */
+/* variables */
+/* plug-in */
+ArchPlugin arch_plugin =
+{
+	NULL,
+	"i586",
+	NULL,
+	_i586_registers,
+	_i586_instructions,
+	_i386_write,
+	NULL
+};
diff --git a/src/arch/i586.ins b/src/arch/i586.ins
new file mode 100644
index 0000000..8cdd63e
--- /dev/null
+++ b/src/arch/i586.ins
@@ -0,0 +1,20 @@
+/* $Id$ */
+/* Copyright (c) 2011 Pierre Pronchery <khorben@defora.org> */
+/* This file is part of DeforaOS Devel asm */
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+
+
+/* instructions */
+/* RDTSC	0x0f31		2					*/
+{ "rdtsc",	0x0f31,		OP2F, AOT_NONE,   AOT_NONE,  AOT_NONE	},
diff --git a/src/arch/project.conf b/src/arch/project.conf
index b5ae78c..6d9f21a 100644
--- a/src/arch/project.conf
+++ b/src/arch/project.conf
@@ -1,8 +1,8 @@
-targets=i386,i386_real,i486,i686,sparc
+targets=i386,i386_real,i486,i586,i686,sparc
 cppflags_force=-I ../../include
 cflags_force=-W
 cflags=-Wall -fPIC -pedantic
-dist=Makefile,common.ins,i386.h,i386.ins,i386.reg,i486.ins,i686.ins,i686.reg,null.ins,sparc.ins,sparc.reg
+dist=Makefile,common.ins,i386.h,i386.ins,i386.reg,i486.ins,i586.ins,i686.ins,i686.reg,null.ins,sparc.ins,sparc.reg
 
 [i386]
 type=plugin
@@ -28,6 +28,14 @@ install=$(LIBDIR)/asm/arch
 [i486.c]
 depends=common.ins,null.ins,i386.h,i386.ins,i386.reg,i486.ins
 
+[i586]
+type=plugin
+sources=i586.c
+install=$(LIBDIR)/asm/arch
+
+[i586.c]
+depends=common.ins,null.ins,i386.h,i386.ins,i386.reg,i486.ins,i586.ins
+
 [i686]
 type=plugin
 sources=i686.c
diff --git a/test/Makefile b/test/Makefile
index 533a82c..b8aa835 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,4 +1,4 @@
-TARGETS	= i386.o i386_real.o i486.o i686.o sparc.o
+TARGETS	= i386.o i386_real.o i486.o i586.o i686.o sparc.o
 PREFIX	= /usr/local
 DESTDIR	= 
 BINDIR	= $(PREFIX)/bin
@@ -21,6 +21,9 @@ i386_real.o_ASFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(ASFLAGS) -a i386_real -f flat
 i486.o_OBJS = i486.o
 i486.o_ASFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(ASFLAGS) -a i486 -f flat
 
+i586.o_OBJS = i586.o
+i586.o_ASFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(ASFLAGS) -a i586 -f flat
+
 i686.o_OBJS = i686.o
 i686.o_ASFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(ASFLAGS) -a i686 -f flat
 
@@ -36,6 +39,9 @@ i386_real.o: i386_real.S ../src/asm
 i486.o: i486.S ../src/asm
 	$(AS) $(i486.o_ASFLAGS) -o i486.o i486.S
 
+i586.o: i586.S ../src/asm
+	$(AS) $(i586.o_ASFLAGS) -o i586.o i586.S
+
 i686.o: i686.S ../src/asm
 	$(AS) $(i686.o_ASFLAGS) -o i686.o i686.S
 
@@ -43,7 +49,7 @@ sparc.o: sparc.S ../src/asm
 	$(AS) $(sparc.o_ASFLAGS) -o sparc.o sparc.S
 
 clean:
-	$(RM) -- $(i386.o_OBJS) $(i386_real.o_OBJS) $(i486.o_OBJS) $(i686.o_OBJS) $(sparc.o_OBJS)
+	$(RM) -- $(i386.o_OBJS) $(i386_real.o_OBJS) $(i486.o_OBJS) $(i586.o_OBJS) $(i686.o_OBJS) $(sparc.o_OBJS)
 
 distclean: clean
 	$(RM) -- $(TARGETS)
diff --git a/test/i586.S b/test/i586.S
new file mode 100644
index 0000000..5c1bf12
--- /dev/null
+++ b/test/i586.S
@@ -0,0 +1,3 @@
+/* $Id$ */
+.text
+	rdtsc					/* 0f 31		*/
diff --git a/test/project.conf b/test/project.conf
index baf7f95..820fc80 100644
--- a/test/project.conf
+++ b/test/project.conf
@@ -1,4 +1,4 @@
-targets=i386.o,i386_real.o,i486.o,i686.o,sparc.o
+targets=i386.o,i386_real.o,i486.o,i586.o,i686.o,sparc.o
 as=../src/asm
 dist=Makefile
 
@@ -26,6 +26,14 @@ sources=i486.S
 asflags=-a i486 -f flat
 depends=../src/asm
 
+[i586.o]
+type=object
+sources=i586.S
+
+[i586.S]
+asflags=-a i586 -f flat
+depends=../src/asm
+
 [i686.o]
 type=object
 sources=i686.S