diff --git a/include/video.h b/include/video.h
index c5af8d5..fa1d968 100755
--- a/include/video.h
+++ b/include/video.h
@@ -17,5 +17,5 @@ u32 print(u8* string);
 u32 printf (const u8 *string, ...);
 void changevc(u8 vc);
 u8* itoa(u64 num, u8* str, u8 base, u64 dim, u8 achar);
-u8* sitoa(int num, u8* str, u32 dim);
+u8* sitoa(u64 num, u8 * str, u64 dim);
 
diff --git a/lib/multiboot.c b/lib/multiboot.c
index 0fa3914..454d503 100644
--- a/lib/multiboot.c
+++ b/lib/multiboot.c
@@ -13,12 +13,12 @@ u32 addr=infobloc;
 struct multiboot_tag *tag;
 unsigned size = *(unsigned *) addr;
 if (addr & 7) print("Non aligne...");
-printf(" Taille :%X\r\n", (u32)size);
+printf(" Taille :% 4u\r\n", (u32)size);
 for (tag = (struct multiboot_tag *) (addr + 8);
             tag->type != MULTIBOOT_TAG_TYPE_END;
             tag = (struct multiboot_tag *) ((u8 *) tag + ((tag->size + 7) & ~7)))
          {
-           printf ("Tag 0x%x, Taille 0x%x\r\n", tag->type, tag->size);
+           printf ("--- Tag % 4u, Taille % 4u\r\n", tag->type, tag->size);
            switch (tag->type)
              {
              case MULTIBOOT_TAG_TYPE_CMDLINE:
@@ -30,15 +30,15 @@ for (tag = (struct multiboot_tag *) (addr + 8);
                        ((struct multiboot_tag_string *) tag)->string);
                break;
              case MULTIBOOT_TAG_TYPE_MODULE:
-               printf ("Module %x-%x. Command line %s\r\n",
+               printf ("Module %X-%X. Command line %s\r\n",
                        ((struct multiboot_tag_module *) tag)->mod_start,
                        ((struct multiboot_tag_module *) tag)->mod_end,
                        ((struct multiboot_tag_module *) tag)->cmdline);
                break;
              case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
-               printf ("Memoire basse : %uKB, memoire haute = %uKB\r\n",
-                       ((struct multiboot_tag_basic_meminfo *) tag)->mem_lower,
-                       ((struct multiboot_tag_basic_meminfo *) tag)->mem_upper);
+               printf ("Memoire basse : %H, memoire haute = %lH\r\n",
+                       ((struct multiboot_tag_basic_meminfo *) tag)->mem_lower<<10,
+                       ((u64)((struct multiboot_tag_basic_meminfo *) tag)->mem_upper)<<10);
                break;
              case MULTIBOOT_TAG_TYPE_BOOTDEV:
                printf ("Peripherique de demarrage : %x,%u,%u\r\n\r\n",
diff --git a/lib/video.c b/lib/video.c
index 134f452..16335af 100755
--- a/lib/video.c
+++ b/lib/video.c
@@ -308,14 +308,15 @@ u32 print(u8 * string)
 
 u32 printf(const u8 * string, ...)
 {
-	va_list args;
+	va_list args,argstemp;
 	u64 sizes[] = { 0xFF, 0xFFFF, 0xFFFFFFFF, 0xFFFFFFFFFFFFFFFF };
+	u8 units[][4] = { "o\000\000", "kio", "mio", "gio", "tio", "pio" };
 	u8 strbase2[] = "0xb\000";
 	u8 strbase8[] = "0xo\000";
 	u8 strbase16[] = "0x\000";
 	u8 hexadecimal[] = "*0x\000";
 	u8 achar, temp;
-	u8 asize, charadd;
+	u8 asize, charadd, unit;
 	u8 buffer[buffersize];
 	u8 *str = string;
 	u8 *strtemp;
@@ -353,6 +354,27 @@ u32 printf(const u8 * string, ...)
                 if (asize>3) asize=3;
 				flag = true;
 				break;
+			case '1':
+			case '2':
+			case '3':
+                asize=0;
+                flag = true;
+				break;
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+                asize=1;
+                flag = true;
+				break;
+			case '8':
+                asize=2;
+                flag = true;
+				break;
+			case '9':
+                asize=3;
+                flag = true;
+				break;
 			case 'u':
                 if (asize==0)
 				    num = (u64) va_arg(args, u8);
@@ -390,6 +412,28 @@ u32 printf(const u8 * string, ...)
 				counter++;
 				flag = false;
 				break;
+            case 'H':
+                if (asize==0)
+				    num = (u64) va_arg(args, u8);
+                else if (asize==1)
+                    num = (u64) va_arg(args, u16);
+                else if (asize==2)
+                    num = (u64) va_arg(args, u32);
+                else
+                    num = (u64) va_arg(args, u64);
+				if (charadd == 0xFF)
+					charadd = ' ';
+                unit=0;     
+                while(num>1024*10)
+                {
+                    num=num>>10;
+                    unit++;
+                }   
+				sitoa(num, &buffer, sizes[asize]);
+				counter += print(&buffer);
+                print(units[unit]);
+				flag = false;
+				break;
 			case 'd':
 			case 'i':
                 if (asize==0)
@@ -493,12 +537,16 @@ u8 *itoa(u64 orignum, u8 * str, u8 base, u64 dim, u8 achar)
 		break;
 	}
 	for (i = 0; i < size; i++) {
+		if (num == 0) {
+            if (achar == 0) break;
+            *(pointer++) = achar;
+        }
+        else
+        {
 		u64 result = num % (u32) base;
-		*(pointer++) =
-		    (result > 9) ? (result - 10) + 'a' : result + '0';
+		*(pointer++) = (result > 9) ? (result - 10) + 'a' : result + '0';
 		num = num / (u32) base;
-		if ((num == 0) && (achar == 0))
-			break;
+        }
 	}
 	*pointer = '\000';
 	strinvert(str);
@@ -509,7 +557,7 @@ u8 *itoa(u64 orignum, u8 * str, u8 base, u64 dim, u8 achar)
 
 /* converti un entier en chaine de caractère */
 
-u8 *sitoa(int num, u8 * str, u32 dim)
+u8 *sitoa(u64 num, u8 * str, u64 dim)
 {
 	u8 *pointer = str;
 	bool isNegative = false;
@@ -519,12 +567,12 @@ u8 *sitoa(int num, u8 * str, u32 dim)
 		*pointer = '\000';
 		return str;
 	}
-	if (num < 0) {
+	if ((((dim+1)>>1)&num)>0) {
 		isNegative = true;
-		num = -num;
+		num = (~num&dim)+1;
 	}
 	while (num != 0) {
-		u32 result = num % 10;
+		u64 result = num % 10;
 		*(pointer++) =
 		    (result > 9) ? (result - 10) + 'a' : result + '0';
 		num = num / 10;
diff --git a/makefile b/makefile
index 51eb030..4d8bf45 100755
--- a/makefile
+++ b/makefile
@@ -78,7 +78,7 @@ qemu-debug64:
 	(killall qemu-system-x86_64;qemu-system-x86_64 -m 1G -drive format=raw,file=./final/harddiskuefi.img.final --bios /usr/share/qemu/OVMF.fd -s -S &)
 
 qemu:
-	(killall qemu-system-i386;qemu-system-i386 -m 5G -drive format=raw,file=./final/harddisk.img.final --enable-kvm -cpu host -s &)  
+	(killall qemu-system-i386;qemu-system-i386 -m 1G -drive format=raw,file=./final/harddisk.img.final --enable-kvm -cpu host -s &)  
 
 qemu64:
 	(killall qemu-system-x86_64;qemu-system-x86_64 -m 1G -drive format=raw,file=./final/harddiskuefi.img.final --bios /usr/share/qemu/OVMF.fd --enable-kvm -cpu host -s &)