diff --git a/config.h b/config.h
index 5492e9d2..560d2aa8 100644
--- a/config.h
+++ b/config.h
@@ -1,3 +1,5 @@
+#include <ultra64.h>
+
 #ifndef S2D_CONFIG_H
 #define S2D_CONFIG_H
 
@@ -24,10 +26,13 @@ extern Gfx *gdl_head;
 
 // an allocator function of the format void *alloc(size_t bytes)
 #define alloc alloc_display_list
+extern void *alloc(size_t);
 
 // your init functions for the RDP/RSP
 #define my_rdp_init my_rdp_init
 #define my_rsp_init my_rsp_init
+extern void my_rsp_init(void);
+extern void my_rdp_init(void);
 
 // The frame timer that is used to time s2d_type_print
 #define s2d_timer gGlobalTimer
diff --git a/fixed_point_math.c b/fixed_point_math.c
index bff61c74..a9fe0b4a 100644
--- a/fixed_point_math.c
+++ b/fixed_point_math.c
@@ -13,8 +13,9 @@
 //     Convert the number to floating point as if it were an integer, in other words remove the binary point
 //     Multiply by 2^−n
 
-f32 qtof(int q) {
-	return ((float)q) * 0.00001525878f;
+f32 qtof(int q, int decimal_n) {
+	f32 mul = (1.0f / (float) (1 << decimal_n));
+	return ((float)q) * mul;
 }
 
 // Float to Q
@@ -23,8 +24,8 @@ f32 qtof(int q) {
 
 //     Multiply the floating point number by 2^n
 //     Round to the nearest integer
-int ftoq(f32 f) {
-	f *= (65536.0f);
+int ftoq(f32 f, int decimal_n) {
+	f *= (float) (1 << decimal_n);
 	return (int)f;
 }
 
diff --git a/init.c b/init.c
index ef3e5c11..27f8dcf4 100644
--- a/init.c
+++ b/init.c
@@ -1,8 +1,11 @@
 #include <ultra64.h>
 #include <PR/gs2dex.h>
+#include "config.h"
 #include "init.h"
+#include "s2d_error.h"
 
 void s2d_init(void) {
+	s2d_error_y = TEX_HEIGHT;
 	gSPLoadUcode(gdl_head++, s2d_text, s2d_data);
 }
 
diff --git a/s2d_error.c b/s2d_error.c
new file mode 100644
index 00000000..dfa25bbc
--- /dev/null
+++ b/s2d_error.c
@@ -0,0 +1,23 @@
+#include "config.h"
+#include "s2d_print.h"
+#include "s2d_error.h"
+
+int s2d_error_y = TEX_HEIGHT;
+
+int s2d_check_align(int align) {
+	if (align < ALIGN_LEFT || align > ALIGN_RIGHT) {
+		s2d_print_alloc(TEX_WIDTH, s2d_error_y, ALIGN_LEFT, "ERROR: invalid alignment");
+		s2d_error_y += TEX_HEIGHT;
+		return -1;
+	}
+	return 0;
+}
+
+int s2d_check_str(const char *str) {
+	if (str == NULL || ((u32)str & 0x80000000) == 0) {
+		s2d_print_alloc(TEX_WIDTH, s2d_error_y, ALIGN_LEFT, "ERROR: bad string, or no string specified");
+		s2d_error_y += TEX_HEIGHT;
+		return -1;
+	}
+	return 0;
+}
diff --git a/s2d_error.h b/s2d_error.h
new file mode 100644
index 00000000..d4b5703a
--- /dev/null
+++ b/s2d_error.h
@@ -0,0 +1,9 @@
+#ifndef S2D_ERROR_H
+#define S2D_ERROR_H
+
+extern int s2d_check_align(int align);
+extern int s2d_check_str(const char *str);
+
+extern int s2d_error_y;
+
+#endif
\ No newline at end of file
diff --git a/s2d_parse.c b/s2d_parse.c
index af417984..7a874972 100644
--- a/s2d_parse.c
+++ b/s2d_parse.c
@@ -8,8 +8,11 @@
 #include "s2d_draw.h"
 #include "s2d_print.h"
 #include "s2d_ustdlib.h"
+#include "s2d_error.h"
 
-void s2d_snprint(int x, int y, int align, const char *str, uObjMtx *buf, int len) {
+static int s2d_width(const char *str, int line, int len);
+
+static void s2d_snprint(int x, int y, int align, const char *str, uObjMtx *buf, int len) {
 	char *p = str;
 	int tmp_len = 0;
 	int orig_x = x;
@@ -115,7 +118,7 @@ void s2d_snprint(int x, int y, int align, const char *str, uObjMtx *buf, int len
 			default:
 				if (current_char != '\0' && current_char != CH_SEPARATOR) {
 					draw_s2d_glyph(current_char, x, y, (buf++));
-					(x += (s2d_kerning_table[current_char] * myScale));
+					(x += (s2d_kerning_table[(int) current_char] * myScale));
 				}
 		}
 		if (*p == '\0') break;
@@ -127,16 +130,31 @@ void s2d_snprint(int x, int y, int align, const char *str, uObjMtx *buf, int len
 }
 
 void s2d_print(int x, int y, int align, const char *str, uObjMtx *buf) {
+	if (s2d_check_align(align) != 0) return;
+	if (s2d_check_str(str)     != 0) return;
+
 	s2d_snprint(x, y, align, str, buf, s2d_strlen(str));
 }
 
 void s2d_print_alloc(int x, int y, int align, const char *str) {
-	uObjMtx *b = alloc(sizeof(uObjMtx) * s2d_strlen(str));
-	s2d_snprint(x, y, align, str, b, s2d_strlen(str));
+	int len;
+
+	if (s2d_check_align(align) != 0) return;
+	if (s2d_check_str(str)     != 0) return;
+
+	len = s2d_strlen(str);
+
+	uObjMtx *b = alloc(sizeof(uObjMtx) * len);
+	s2d_snprint(x, y, align, str, b, len);
 }
 
 void s2d_type_print(int x, int y, int align, const char *str, uObjMtx *buf, int *pos) {
-	int len = s2d_strlen(str);
+	int len;
+
+	if (s2d_check_align(align) != 0) return;
+	if (s2d_check_str(str)     != 0) return;
+	
+	len = s2d_strlen(str);
 
 	s2d_snprint(x, y, align, str, buf, *pos);
 	if (s2d_timer % 2 == 0) {
@@ -146,7 +164,7 @@ void s2d_type_print(int x, int y, int align, const char *str, uObjMtx *buf, int
 	}
 }
 
-int s2d_width(const char *str, int line, int len) {
+static int s2d_width(const char *str, int line, int len) {
 	char *p = str;
 	int tmp_len = 0;
 	int curLine = 0;
@@ -200,7 +218,7 @@ int s2d_width(const char *str, int line, int len) {
 				break;
 			default:
 				if (current_char != '\0' && curLine == line)
-					width += s2d_kerning_table[current_char] * scale;
+					width += s2d_kerning_table[(int) current_char] * scale;
 		}
 		if (*p == '\0') break;
 		p++;
@@ -218,7 +236,7 @@ int s2d_width(const char *str, int line, int len) {
 // 	if (last_chr >= 0) {
 // 		dst[last_chr] = '\0';
 // 	}
-// 	s2d_print(x, y, dst, buf);
+// 	s2d_print(x, y, align, dst, buf);
 // }
 
 
diff --git a/s2d_print.h b/s2d_print.h
index d1b098e3..0929c3ae 100644
--- a/s2d_print.h
+++ b/s2d_print.h
@@ -29,7 +29,6 @@
 #define ALIGN_CENTER 1
 #define ALIGN_RIGHT 2
 
-extern void s2d_snprint(int x, int y, int align, const char *str, uObjMtx *buf, int len);
 extern void s2d_print(int x, int y, int align, const char *str, uObjMtx *buf);
+extern void s2d_print_alloc(int x, int y, int align, const char *str);
 extern void s2d_type_print(int x, int y, int align, const char *str, uObjMtx *buf, int *pos);
-extern void s2d_vsprint(int x, int y, int align, uObjMtx *buf, const char *str, ...);