diff --git a/inc/mouse.h b/inc/mouse.h
index bf41124..46fab17 100644
--- a/inc/mouse.h
+++ b/inc/mouse.h
@@ -12,6 +12,6 @@ typedef struct {
 } MouseData;
 
 // Чтение мыши с порта
-MouseData read_mouse(volatile u8* port);
+void read_mouse(MouseData* dst, volatile u8* port);
 
 #endif
diff --git a/src/main.c b/src/main.c
index 818433a..f64fbb4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,7 +14,8 @@ int main() {
 	char buf[40]; //буфер строки для вывода на экран
 
 	while(TRUE) {
-		MouseData m1 = read_mouse(PORT1);
+		MouseData m1;
+		read_mouse(&m1, PORT1);
 		sprintf(buf, "+%X%X%X%X %X %X %X%X %X%X", 
 				m1.nibbles[0], m1.nibbles[1], m1.nibbles[2], m1.nibbles[3],
 				m1.nibbles[4], m1.nibbles[5], m1.nibbles[6], m1.nibbles[7],
@@ -42,7 +43,8 @@ int main() {
 			VDP_drawText(buf, 1, 24);
 		}
 		
-		MouseData m2 = read_mouse(PORT2);
+		MouseData m2;
+		read_mouse(&m2, PORT2);
 		sprintf(buf, "%X%X%X%X %X %X %X%X %X%X+", 
 				m2.nibbles[0], m2.nibbles[1], m2.nibbles[2], m2.nibbles[3],
 				m2.nibbles[4], m2.nibbles[5], m2.nibbles[6], m2.nibbles[7],
diff --git a/src/mouse.c b/src/mouse.c
index d7be0a1..1420cb0 100644
--- a/src/mouse.c
+++ b/src/mouse.c
@@ -14,41 +14,34 @@ static inline void delay(void) {
     );
 }
 
-MouseData read_mouse(volatile u8* port) {
-    u8 nibbles[16];
-    MouseData md = {0};
+void read_mouse(MouseData* dst, volatile u8* port) {
+
+    dst->valid = 0;
 
     Z80_HALT = 0x0100;
     *port = 0x60; delay();
 
-    nibbles[0] = *port & 0x0F;
+    dst->nibbles[0] = *port & 0x0F;
     for(int i=1; i<10; i++) {
         *port = (i&1) ? 0x20 : 0x00;
         delay();
-        nibbles[i] = *port & 0x0F;
+        dst->nibbles[i] = *port & 0x0F;
         delay();
     }
 
     *port = 0x60; delay();
     Z80_HALT = 0x0000;
 
-    // копируем нибблы для вывода RAW
-    for(int i=0;i<10;i++) md.nibbles[i] = nibbles[i];
-
     // проверка сигнатуры 0BFF
-    if (nibbles[0]==0x0 && nibbles[1]==0xB && nibbles[2]==0xF && nibbles[3]==0xF) {
-        md.valid = 1;
-        s16 dx = (nibbles[6] << 4) | nibbles[7];
-        s16 dy = (nibbles[8] << 4) | nibbles[9];
-        if (nibbles[4] & 8) dy = 255;
-        if (nibbles[4] & 4) dx = 255;
-        if (nibbles[4] & 2) dy |= 0xFF00; // sign-extend
-        if (nibbles[4] & 1) dx |= 0xFF00;
+    if (dst->nibbles[0]==0x0 && dst->nibbles[1]==0xB && dst->nibbles[2]==0xF && dst->nibbles[3]==0xF) {
+        dst->valid = 1;
+        dst->dx = (dst->nibbles[6] << 4) | dst->nibbles[7];
+        dst->dy = (dst->nibbles[8] << 4) | dst->nibbles[9];
+        if (dst->nibbles[4] & 8) dst->dy = 255;
+        if (dst->nibbles[4] & 4) dst->dx = 255;
+        if (dst->nibbles[4] & 2) dst->dy |= 0xFF00; // sign-extend
+        if (dst->nibbles[4] & 1) dst->dx |= 0xFF00;
 
-        md.dx = dx;
-        md.dy = dy;
-        md.buttons = nibbles[5];
+        dst->buttons = dst->nibbles[5];
     }
-
-    return md;
 }