diff --git a/libftasm/Makefile b/libftasm/Makefile
index 2c063883..cf3a6087 100644
--- a/libftasm/Makefile
+++ b/libftasm/Makefile
@@ -105,13 +105,6 @@ test: $(NAME) test.c
 	@gcc test.c -I $(INC_DIR) -L. -lfts -o test
 	@printf "\r\033[38;5;117m✓ MAKE test\033[0m\033[K\n"
 
-debug: $(NAME) debug.c
-	@gcc debug.c -I $(INC_DIR) -L. -lfts -o debug
-	@printf "\r\033[38;5;117m✓ MAKE debug\033[0m\033[K\n"
-
-run-dbg: debug
-	lldb ./debug
-
 .PHONY :		fclean clean re run-gdb
 
 -include $(OBJS:.o=.d)
diff --git a/libftasm/debug.c b/libftasm/debug.c
deleted file mode 100644
index 5a6741e7..00000000
--- a/libftasm/debug.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include "libft.h"
-
-int	main(void)
-{
-	ft_puts("h2g2");
-	return (0);
-}
diff --git a/libftasm/srcs/ft_cat.s b/libftasm/srcs/ft_cat.s
index d174b885..1e6416ca 100644
--- a/libftasm/srcs/ft_cat.s
+++ b/libftasm/srcs/ft_cat.s
@@ -1,10 +1,8 @@
 global _ft_cat
 global ft_cat
 
-extern ft_putchar
-
 %define STDOUT			1
-%define BUFF_SIZE		10
+%define BUFF_SIZE		1024
 
 section .bss
 	buf: resb BUFF_SIZE
diff --git a/libftasm/srcs/ft_putchar.s b/libftasm/srcs/ft_putchar.s
index 3a005c66..e29d6655 100644
--- a/libftasm/srcs/ft_putchar.s
+++ b/libftasm/srcs/ft_putchar.s
@@ -27,6 +27,7 @@ ft_putchar:
 
 	; success case then return c
 	pop		rax
+	movzx	rax, al				; cast to char
 	ret
 
 err:
diff --git a/libftasm/srcs/ft_strdup.s b/libftasm/srcs/ft_strdup.s
index 7953ed33..de78e1fa 100644
--- a/libftasm/srcs/ft_strdup.s
+++ b/libftasm/srcs/ft_strdup.s
@@ -12,19 +12,24 @@ ft_strdup:
 	mov		rax, 0
 	cmp		rdi, 0
 	je		end
+
 	push	rdi
 	call	_ft_strlen
 	inc		rax
 	push	rax
 	mov		rdi, rax
+
+	sub		rsp, 8		; align stack to 16 bytes, x86_64 or mach don't know
 	call	_malloc
+	add		rsp, 8
+
+	pop		rcx
+	pop		rsi
 	cmp		rax, 0
 	je		end
 
 	mov		rdi, rax
-	pop		rcx
-	pop		rsi
-	cld
+	cld					; clear the directon flag
 	rep		movsb
 end:
 	ret
diff --git a/libftasm/srcs/ft_strlen.s b/libftasm/srcs/ft_strlen.s
index 2dbe5bb4..fc41dbfe 100644
--- a/libftasm/srcs/ft_strlen.s
+++ b/libftasm/srcs/ft_strlen.s
@@ -3,14 +3,16 @@ global ft_strlen
 
 _ft_strlen:
 ft_strlen:
-	mov rax, 0
-	cmp rdi, 0
-	je end
-loop:
-	cmp byte [rdi], 0
-	je end
-	inc rax
-	inc rdi
-	jmp loop
+	mov		rax, 0
+	cmp		rdi, 0
+	je		end
+t
+	mov		rcx, -1
+	cld
+	repnz	scasb
+
+	not		rcx
+	lea		rax, [rcx - 1]
+
 end:
 	ret
diff --git a/libftasm/test.c b/libftasm/test.c
index cd2dc492..d32a725f 100644
--- a/libftasm/test.c
+++ b/libftasm/test.c
@@ -6,11 +6,6 @@ int ft_putstr(const char *str)
 	return (write(1, str, strlen(str)));
 }
 
-/* int ft_putchar(const char c) */
-/* { */
-/* 	return (write(1, &c, 1)); */
-/* } */
-
 int ft_putnstr(const char *str, size_t n)
 {
 	return (write(1, str, n));
@@ -400,26 +395,26 @@ int test_strdup()
 	}
 	str = ft_strdup("Coucou");
 	str_cmp = strdup("Coucou");
-	/* len = strlen(str); */
-	/* len_cmp = strlen(str_cmp); */
-	/* if (len != len_cmp) */
-	/* { */
-	/* 	printf("FAILED: len is %d vs %d\n", len, len_cmp); */
-	/* 	return (1); */
-	/* } */
-	/* i = -1; */
-	/* while (++i < len) */
-	/* { */
-	/* 	if (str[i] != str_cmp[i]) */
-	/* 	{ */
-	/* 		ft_putnstr(str, len); */
-	/* 		ft_putnstr(str_cmp, len); */
-	/* 		printf("FAILED: %c vs %c\n", str[i], str_cmp[i]); */
-	/* 		return (1); */
-	/* 	} */
-	/* } */
-	/* free(str); */
-	/* free(str_cmp); */
+	len = strlen(str);
+	len_cmp = strlen(str_cmp);
+	if (len != len_cmp)
+	{
+		printf("FAILED: len is %d vs %d\n", len, len_cmp);
+		return (1);
+	}
+	i = -1;
+	while (++i < len)
+	{
+		if (str[i] != str_cmp[i])
+		{
+			ft_putnstr(str, len);
+			ft_putnstr(str_cmp, len);
+			printf("FAILED: %c vs %c\n", str[i], str_cmp[i]);
+			return (1);
+		}
+	}
+	free(str);
+	free(str_cmp);
 
 	return (0);
 }
@@ -427,13 +422,15 @@ int test_strdup()
 int test_cat(char ** argv)
 {
 	ft_putstr(__func__); ft_putstr(":\n");
+
 	/* ft_putstr("Wait for a user input:\n"); */
 	/* ft_cat(0); */
-	ft_putstr("\ntest.c:\n");
-	ft_cat(open(__FILE__, O_RDONLY));
-	ft_putstr("\ntest binary:\n");
-	ft_cat(open(argv[0], O_RDONLY));
-	ft_cat(-42);
+
+	/* ft_putstr("\ntest.c:\n"); */
+	/* ft_cat(open(__FILE__, O_RDONLY)); */
+
+	/* ft_putstr("\ntest binary:\n"); */
+	/* ft_cat(open("test", O_RDONLY)); */
 	return (0);
 }
 
@@ -510,16 +507,15 @@ int main(int argc, char **argv)
 			test_memcpy() ||
 			test_strdup())
 		return (1);
-	exit(1);
 	ft_putstr("\nPART BONUS:\n_______\n");
 	if (test_isupper() ||
 			test_islower() ||
-			test_isupper())
-			/* test_putchar()) */
+			test_isupper() ||
+			test_putchar())
 		return (1);
 	ft_putstr("\nPART 3:\n_______\n");
 	if (test_cat(argv))
 		return (1);
-	puts("\033c\n\033[38;5;117mALL PASSED:\n___________\n\033[0m");
+	puts("\033c\n\033[38;5;117mALL PASSED\n___________\n\033[0m");
 	return (0);
 }