diff --git a/src/arch/linux/devices.c b/src/arch/linux/devices.c
index 9ff81b9..8e9e7d0 100644
--- a/src/arch/linux/devices.c
+++ b/src/arch/linux/devices.c
@@ -79,14 +79,13 @@ i32 screen_read(void *data, u8 *buffer, u32 size) {
 
 i32 screen_write(void *data, const u8 *buffer, u32 size) {
   ScreenDeviceData *screen = (ScreenDeviceData *)data;
-  USED(buffer);
 
   if (size > screen->size * sizeof(u8)) {
     return -1;
   }
 
   if (screen->texture && screen->renderer) {
-    SDL_UpdateTexture(screen->texture, nil, &buffer[screen->pos],
+    SDL_UpdateTexture(screen->texture, nil, buffer,
                       screen->width);
 
     SDL_RenderClear(screen->renderer);
diff --git a/src/arch/linux/main.c b/src/arch/linux/main.c
index a12117d..b61dc56 100644
--- a/src/arch/linux/main.c
+++ b/src/arch/linux/main.c
@@ -146,7 +146,9 @@ bool compileAndSave(const char *source_file, const char *output_file, VM *vm) {
     printf("Parse failed.\n");
     return false;
   } else {
+#ifdef ASM_DEBUG
     expr_print(ast, 0);
+#endif
     assemble(vm, ast);
     expr_free(ast);
 
@@ -241,9 +243,6 @@ void register_sdl_devices(VM *vm) {
   screen_data.width = 640;
   screen_data.height = 480;
   screen_data.size = 640 * 480;
-  screen_data.pos = vm->mp;
-  vm->mp += screen_data.size; /* advance memory pointer */
-  vm->frames[vm->fp].end = vm->mp;
 
   vm_register_device(vm, "/dev/screen/0", "screen", &screen_data, &screen_ops);
 
@@ -254,9 +253,6 @@ void register_sdl_devices(VM *vm) {
   mouse_data.btn3 = 0;
   mouse_data.btn4 = 0;
   mouse_data.size = 12;
-  mouse_data.pos = vm->mp;
-  vm->mp += mouse_data.size; /* advance memory pointer */
-  vm->frames[vm->fp].end = vm->mp;
 
   vm_register_device(vm, "/dev/mouse/0", "mouse", &mouse_data, &mouse_ops);
 
diff --git a/src/tools/assembler.c b/src/tools/assembler.c
index cc45592..1950d93 100644
--- a/src/tools/assembler.c
+++ b/src/tools/assembler.c
@@ -952,4 +952,4 @@ void assemble(VM *vm, ExprNode *program) {
     free(table.symbols[i].name);
   }
   free(table.symbols);
-}
\ No newline at end of file
+}
diff --git a/src/tools/parser.c b/src/tools/parser.c
index 72eac4c..a17c03d 100644
--- a/src/tools/parser.c
+++ b/src/tools/parser.c
@@ -251,4 +251,4 @@ void expr_print(ExprNode *node, int indent) {
       expr_print(node->children[i], indent + 1);
     }
   }
-}
\ No newline at end of file
+}
diff --git a/src/tools/parser.h b/src/tools/parser.h
index 594eca7..53ac41b 100644
--- a/src/tools/parser.h
+++ b/src/tools/parser.h
@@ -22,4 +22,4 @@ void expr_free(ExprNode *node);
 void expr_print(ExprNode *node, int indent);
 void *safe_malloc(size_t size);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/vm/common.h b/src/vm/common.h
index 83f28eb..3a3d579 100644
--- a/src/vm/common.h
+++ b/src/vm/common.h
@@ -1,7 +1,6 @@
 #ifndef ZRE_COMMON_H
 #define ZRE_COMMON_H
 
-#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -12,6 +11,10 @@ typedef int16_t i16;
 typedef uint32_t u32;
 typedef int32_t i32;
 
+#define true 1
+#define false 0
+#define bool u8
+
 #define nil NULL
 
 #define USED(x) ((void)(x))
diff --git a/src/vm/device.h b/src/vm/device.h
index c6634be..4b29d93 100644
--- a/src/vm/device.h
+++ b/src/vm/device.h
@@ -8,4 +8,4 @@ Device* find_device_by_path(VM *vm, const char *path);
 Device* find_device_by_type(VM *vm, const char *type);
 i32 find_devices_by_type(VM *vm, const char *type, Device **results, uint32_t max_results);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/test/box.asm.lisp b/test/box.asm.lisp
index 9dd311e..96ed57c 100644
--- a/test/box.asm.lisp
+++ b/test/box.asm.lisp
@@ -5,8 +5,6 @@
     (load-immediate $0 &screen-namespace)
     (load-immediate $11 0)
     (syscall OPEN $0 $11)
-    ; draw to the device because otherwise the screen wont open
-    (syscall WRITE $0 $0 $0)
 
     (load-immediate $16 1) ; device info call
     (load-immediate $17 16) ; sizeof screen device info
@@ -15,10 +13,11 @@
     (load-immediate $1 12) ; offset for width
     (add-nat $19 $18 $1)
     (load-r $20 $19) ; load width
-    (load-immediate $1 4) ; offset for width
+    (load-immediate $1 8) ; offset for size
     (add-nat $19 $18 $1)
-    (load-r $21 $19) ; load base pointer
-    (add-nat $21 $21 $1) ; need to add offset for fat pointer size
+    (load-r $22 $19) ; load size    
+    (malloc $21 $22) ; malloc frame buffer
+    (syscall WRITE $0 $21 $22)
 
     (load-immediate $16 &mouse-namespace)
 	  (load-immediate $3 12) ; malloc sizeof mouse data
@@ -43,6 +42,8 @@
       (load-immediate $14 20) ; box size
 
       ; first row
+      (push $21)
+      (push $20)
       (load $1 &BLACK)
       (push $1)
       (load-immediate $12 1)
@@ -60,6 +61,8 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
+      (push $21)
+      (push $20)
       (load $1 &WHITE)
       (push $1)
       (load-immediate $12 21)
@@ -78,6 +81,8 @@
       (call &set-color-if-clicked)
 
       ; row 2
+      (push $21)   
+      (push $20)   
       (load $1 &CHARCOAL)
       (push $1)
       (load-immediate $12 1)
@@ -95,6 +100,8 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
+      (push $21)
+      (push $20)
       (load $1 &DARK-GRAY)
       (push $1)
       (load-immediate $12 21)
@@ -113,6 +120,8 @@
       (call &set-color-if-clicked)
 
       ; row 3
+      (push $21)    
+      (push $20)  
       (load $1 &RED)
       (push $1)
       (load-immediate $12 1)
@@ -130,6 +139,8 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
+      (push $21)
+      (push $20)
       (load $1 &ORANGE)
       (push $1)
       (load-immediate $12 21)
@@ -148,6 +159,8 @@
       (call &set-color-if-clicked)
 
       ; row 3
+      (push $21)      
+      (push $20)
       (load $1 &YELLOW)
       (push $1)
       (load-immediate $12 1)
@@ -165,6 +178,8 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
+      (push $21)
+      (push $20)
       (load $1 &GREEN)
       (push $1)
       (load-immediate $12 21)
@@ -183,6 +198,8 @@
       (call &set-color-if-clicked)
 
       ; row 4
+      (push $21)     
+      (push $20) 
       (load $1 &BLUE)
       (push $1)
       (load-immediate $12 1)
@@ -200,6 +217,8 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
+      (push $21)
+      (push $20)
       (load $1 &PURPLE)
       (push $1)
       (load-immediate $12 21)
@@ -217,7 +236,7 @@
       (push $9)             ; is btn1 clicked?
       (call &set-color-if-clicked)
 
-      (syscall WRITE $0 $0 $0)
+      (syscall WRITE $0 $21 $22)
 
       (jump-eq-nat &draw-loop $9 $11)
 
@@ -282,13 +301,24 @@
     (pop $3)   ; y
     (pop $2)   ; x
     (pop $1)   ; color
+    (pop $20)
+    (pop $21)
 
     ; Constants
     (load $4 &GRAY)
+    (load $10 &SELECTED-COLOR)
+    (jump-eq-int &set-selected $10 $1)
+    (jump-eq-int &end-set-selected $4 $4)
+    (label set-selected)
+    (load $4 &DARK-GRAY)
+    (label end-set-selected)
+
     (load-immediate $5 20)       ; outline size
     (load-immediate $6 17)       ; fill size
     (load-immediate $7 2)        ; offset
 
+    (push $21)     ; base
+    (push $20)     ; width
     (push $4)      ; color (gray)
     (push $2)      ; x
     (push $3)      ; y
@@ -299,6 +329,8 @@
     (add-int $8 $2 $7)   ; x + 2
     (add-int $9 $3 $7)   ; y + 2
 
+    (push $21)     ; base
+    (push $20)     ; width
     (push $1)      ; color (original)
     (push $8)      ; x + 2
     (push $9)      ; y + 2
@@ -317,20 +349,8 @@
     (pop $13)        ; y_start
     (pop $11)        ; x_start
     (pop $3)         ; color
-
-    ;; get the screen width dynamically from the device
-    (load-immediate $0 &screen-namespace)
-    (load-immediate $16 1) ; device info call
-    (load-immediate $17 16) ; sizeof screen device info
-    (malloc $18 $17)
-    (syscall IOCTL $0 $16 $18)
-    (load-immediate $1 12) ; offset for width
-    (add-nat $19 $18 $1)
-    (load-r $2 $19) ; load width
-    (load-immediate $1 4) ; offset for width
-    (add-nat $19 $18 $1)
-    (load-r $21 $19) ; load base pointer
-    (add-nat $21 $21 $1) ; need to add offset for fat pointer size
+    (pop $2)         ; width
+    (pop $21)        ; base
 
     ; Constants
     (load-immediate $1 1)        ; increment
@@ -339,6 +359,8 @@
     (mul-int $15 $13 $2)         ; $15 = y * 640
     (add-int $15 $15 $11)        ; $15 += x
     (add-nat $15 $21 $15)       ; $15 = base + pixel_offset
+    (load-immediate $25 4)
+    (add-nat $15 $15 $25) ; need to add offset for fat pointer size
     (register-move $4 $15)
 
     ; Outer loop: height times
diff --git a/test/window.asm.lisp b/test/window.asm.lisp
index c7b4658..6b8915e 100644
--- a/test/window.asm.lisp
+++ b/test/window.asm.lisp
@@ -3,7 +3,6 @@
     (load-immediate $0 &screen-namespace)
     (load-immediate $11 0)
     (syscall OPEN $0 $11)
-    (syscall WRITE $0 $0 $0)
 
     (load-immediate $16 1) ; device info call
     (load-immediate $17 16) ; sizeof screen device info
@@ -12,10 +11,11 @@
     (load-immediate $1 12) ; offset for width
     (add-nat $19 $18 $1)
     (load-r $20 $19) ; load width
-    (load-immediate $1 4) ; offset for width
+    (load-immediate $1 8) ; offset for size
     (add-nat $19 $18 $1)
-    (load-r $21 $19) ; load base pointer
-    (add-nat $21 $21 $1) ; need to add offset for fat pointer size
+    (load-r $22 $19) ; load size
+    (malloc $21 $22) ; malloc frame buffer
+    (syscall WRITE $0 $21 $22)
 
     (load-immediate $16 &mouse-namespace)
 	  (load-immediate $3 12) ; malloc sizeof mouse data
@@ -24,29 +24,33 @@
     (label draw-loop
       ; load mouse click data
 	  	(syscall READ $16 $2 $3 $4)
+      (load-immediate $5 12) ; offset for btn1
+      (add-nat $6 $5 $2)
+      (load-r8 $9 $6) ; load btn1 pressed
+
+      (jump-eq-nat &draw-loop $9 $11)
+
       (load-immediate $5 4) ; offset for x
       (add-nat $6 $5 $2)
       (load-r $7 $6) ; load x
       (load-immediate $5 8) ; offset for y
       (add-nat $6 $5 $2)
       (load-r $8 $6) ; load y
-      (load-immediate $5 12) ; offset for btn1
-      (add-nat $6 $5 $2)
-      (load-r8 $9 $6) ; load btn1 pressed
-      (load-immediate $5 13) ; offset for btn2
-      (add-nat $6 $5 $2)
-      (load-r8 $10 $6) ; load btn2 pressed
-
-      (jump-eq-nat &draw-loop $9 $11)
 
       ; Compute start address: y*width + x
       (mul-nat $15 $8 $20)        ; $15 = y * width
       (add-nat $15 $15 $7)        ; $15 += x
       (add-nat $15 $21 $15)       ; $15 = base + pixel_offset
+      (load-immediate $1 4) ; need to add offset for fat pointer size
+      (add-nat $15 $15 $1)
 
       (load $3 &WHITE) ; color
       (store-8 $15 $3) ; draw color at screen [x,y]
-      (syscall WRITE $0 $0 $0) ; redraw
+      (syscall WRITE $0 $21 $22) ; redraw
+
+      (load-immediate $5 13) ; offset for btn2
+      (add-nat $6 $5 $2)
+      (load-r8 $10 $6) ; load btn2 pressed
 
       (jump-eq-nat &draw-loop $10 $11))
     (halt))