diff --git a/Makefile b/Makefile
index 828db69..ae18967 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ CFLAGS=-Ilib83 -c -mz80 --std-sdcc2x --no-std-crt0 --reserve-regs-iy --opt-code-
 
 OBJS=_crt0.rel clrscr.rel putchar.rel puts.rel exit.rel gotoxy.rel __assert_fail.rel \
      getchar.rel put_int.rel ctype.rel memcpy.rel memset.rel memmove.rel memcmp.rel \
-	 strcpy.rel strlen.rel \
+	 strcpy.rel strlen.rel strncpy.rel \
 	 main.rel
 
 .PHONY: all clean try
diff --git a/lib83/_crt0.c b/lib83/_crt0.c
index 35de3d9..cb0124b 100644
--- a/lib83/_crt0.c
+++ b/lib83/_crt0.c
@@ -3,7 +3,7 @@
 
 extern void main();
 
-void AppHeader() {
+void _start() {
     __asm
         .db 0x80, 0x0F
         .db 0, 0, 0, 0
diff --git a/lib83/assert.h b/lib83/assert.h
index 0edfbb1..f4b508e 100644
--- a/lib83/assert.h
+++ b/lib83/assert.h
@@ -4,6 +4,6 @@
 
 #define assert(expr) ((expr) ? (void) (0) : __assert_fail(#expr, __FILE__, __LINE__, __func__))
 
-extern void __assert_fail(const char *__assertion, const char *__file, unsigned int __line, const char *__function);
+extern void __assert_fail(const char * __assertion, const char * __file, unsigned int __line, const char * __function);
 
 #endif
diff --git a/lib83/memcmp.c b/lib83/memcmp.c
index 2064e9c..0f6ff50 100644
--- a/lib83/memcmp.c
+++ b/lib83/memcmp.c
@@ -4,10 +4,10 @@
 int8_t memcmp(void * buf1, void * buf2, size_t count) {
 	if (!count) return 0;
 
-	while (--count && *(unsigned char*)buf1 == *(unsigned char*)buf2) {
+	while (--count && *(unsigned char *)buf1 == *(unsigned char *)buf2) {
         buf1 = 1 + (unsigned char *)buf1; buf2 = 1 + (unsigned char *)buf2;
     }
 
-	return *(char*)buf1 - *(char*)buf2;
+	return *(char *)buf1 - *(char *)buf2;
 }
 
diff --git a/lib83/stddef.h b/lib83/stddef.h
index 1429181..a1f3a09 100644
--- a/lib83/stddef.h
+++ b/lib83/stddef.h
@@ -2,7 +2,7 @@
 #ifndef _STDDEF_H
 #define _STDDEF_H
 
-#define NULL ((void *)0)
+#define NULL ((void *) 0)
 
 typedef unsigned char uint8_t;
 typedef unsigned short uint16_t;
diff --git a/lib83/string.h b/lib83/string.h
index c33d86b..d4b4e60 100644
--- a/lib83/string.h
+++ b/lib83/string.h
@@ -4,17 +4,17 @@
 
 #include <stddef.h>
 
-extern void *memcpy(void *dest, const void *src, size_t n);
-extern void *memset(void *s, unsigned char c, size_t n);
-extern void *memmove(void *dest, const void *src, size_t n);
-extern int8_t memcmp(const void *s1, const void *s2, size_t n);
+extern void * memcpy(void * dest, const void * src, size_t n);
+extern void * memset(void * s, unsigned char c, size_t n);
+extern void * memmove(void * dest, const void * src, size_t n);
+extern int8_t memcmp(const void * s1, const void * s2, size_t n);
 
-extern char *strcpy(char *dest, const char *src);
-extern char *strncpy(char *dest, const char *src, size_t n);
-extern size_t strlen(const char *s);
-extern int8_t strcmp(const char *s1, const char *s2);
-extern int8_t strncmp(const char *s1, const char *s2, size_t n);
-extern char * strcat(char *dest, const char *src);
+extern char * strcpy(char * dest, const char * src);
+extern char * strncpy(char * dest, const char * src, size_t n);
+extern size_t strlen(const char * s);
+extern int8_t strcmp(const char * s1, const char * s2);
+extern int8_t strncmp(const char * s1, const char * s2, size_t n);
+extern char * strcat(char * dest, const char * src);
 
 #endif
 
diff --git a/lib83/strncpy.c b/lib83/strncpy.c
new file mode 100644
index 0000000..6f06ed3
--- /dev/null
+++ b/lib83/strncpy.c
@@ -0,0 +1,10 @@
+
+#include <string.h>
+
+char * strncpy(char * d, const char * s, size_t n) {
+	register char * d1 = d;
+	while (n && *s) { n--; *d++ = *s++; }
+	while (n--) *d++ = '\0' ;
+	return d1;
+}
+