diff --git a/src/arch/linux/main.c b/src/arch/linux/main.c
index 3e6ab64..a12117d 100644
--- a/src/arch/linux/main.c
+++ b/src/arch/linux/main.c
@@ -419,16 +419,14 @@ i32 main(i32 argc, char *argv[]) {
 
     while (running) {
 #ifdef ASM_DEBUG
-      printf("| %d %s %d\n", vm.code[vm.pc], opcode_to_string(vm.code[vm.pc]),
-             vm.pc);
+      printf("| %s %d\n", opcode_to_string(vm.code[vm.pc]),vm.pc);
 #endif
       running = step_vm(&vm);
     }
   } else {
     while (running) {
 #ifdef ASM_DEBUG
-      printf("| %d %s %d\n", vm.code[vm.pc], opcode_to_string(vm.code[vm.pc]),
-             vm.pc);
+      printf("| %s %d\n", opcode_to_string(vm.code[vm.pc]),vm.pc);
 #endif
       running = step_vm(&vm);
     }
diff --git a/test/box.asm.lisp b/test/box.asm.lisp
index 94ac2cf..9dd311e 100644
--- a/test/box.asm.lisp
+++ b/test/box.asm.lisp
@@ -3,11 +3,23 @@
     ; Open screen
     ; use load immediate because it is a pointer to a string, not a value
     (load-immediate $0 &screen-namespace)
-    (load-immediate $1 0)
-    (syscall OPEN $0 $1)
+    (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
+    (malloc $18 $17)
+    (syscall IOCTL $0 $16 $18)
+    (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
+    (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-immediate $16 &mouse-namespace)
 	  (load-immediate $3 12) ; malloc sizeof mouse data
 	  (malloc $4 $3)
@@ -28,103 +40,244 @@
       (add-nat $6 $5 $2)
       (load-r8 $10 $6) ; load btn2 pressed
 
+      (load-immediate $14 20) ; box size
+
       ; first row
       (load $1 &BLACK)
       (push $1)
-      (load-immediate $1 1)
-      (push $1)
-      (load-immediate $1 1)
-      (push $1)
+      (load-immediate $12 1)
+      (push $12)
+      (load-immediate $13 1)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (load $1 &WHITE)
       (push $1)
-      (load-immediate $1 21)
-      (push $1)
-      (load-immediate $1 1)
-      (push $1)
+      (load-immediate $12 21)
+      (push $12)
+      (load-immediate $13 1)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       ; row 2
       (load $1 &CHARCOAL)
       (push $1)
-      (load-immediate $1 1)
-      (push $1)
-      (load-immediate $1 21)
-      (push $1)
+      (load-immediate $12 1)
+      (push $12)
+      (load-immediate $13 21)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (load $1 &DARK-GRAY)
       (push $1)
-      (load-immediate $1 21)
-      (push $1)
-      (load-immediate $1 21)
-      (push $1)
+      (load-immediate $12 21)
+      (push $12)
+      (load-immediate $13 21)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       ; row 3
       (load $1 &RED)
       (push $1)
-      (load-immediate $1 1)
-      (push $1)
-      (load-immediate $1 41)
-      (push $1)
+      (load-immediate $12 1)
+      (push $12)
+      (load-immediate $13 41)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (load $1 &ORANGE)
       (push $1)
-      (load-immediate $1 21)
-      (push $1)
-      (load-immediate $1 41)
-      (push $1)
+      (load-immediate $12 21)
+      (push $12)
+      (load-immediate $13 41)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       ; row 3
       (load $1 &YELLOW)
       (push $1)
-      (load-immediate $1 1)
-      (push $1)
-      (load-immediate $1 61)
-      (push $1)
+      (load-immediate $12 1)
+      (push $12)
+      (load-immediate $13 61)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (load $1 &GREEN)
       (push $1)
-      (load-immediate $1 21)
-      (push $1)
-      (load-immediate $1 61)
-      (push $1)
+      (load-immediate $12 21)
+      (push $12)
+      (load-immediate $13 61)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       ; row 4
       (load $1 &BLUE)
       (push $1)
-      (load-immediate $1 1)
-      (push $1)
-      (load-immediate $1 81)
-      (push $1)
+      (load-immediate $12 1)
+      (push $12)
+      (load-immediate $13 81)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (load $1 &PURPLE)
       (push $1)
-      (load-immediate $1 21)
-      (push $1)
-      (load-immediate $1 81)
-      (push $1)
+      (load-immediate $12 21)
+      (push $12)
+      (load-immediate $13 81)
+      (push $13)
       (call &draw-outlined-swatch)
 
+      (push $14)            ; box_size (20)
+      (push $13)            ; box_y  
+      (push $12)            ; box_x
+      (push $8)             ; click_y
+      (push $7)             ; click_x
+      (push $1)             ; color
+      (push $9)             ; is btn1 clicked?
+      (call &set-color-if-clicked)
+
       (syscall WRITE $0 $0 $0)
+
       (jump-eq-nat &draw-loop $9 $11)
 
-      ; if click on box then switch color
+      (mul-nat $15 $8 $20)        ; $15 = y * width
+      (add-nat $15 $15 $7)        ; $15 += x
+      (add-nat $15 $21 $15)       ; $15 = base + pixel_offset
 
-      ; else draw the pixel
+      (load $22 &SELECTED-COLOR) ; color
+      (store-8 $15 $22) ; draw color at screen [x,y]
 
       (jump-eq-nat &draw-loop $10 $11))
 
     ; Flush and halt
     (halt))
 
+  (label set-color-if-clicked
+    ; Pop inputs from stack (in reverse order of pushing)
+    (pop $12)       ; $12 = btn1 down?
+    (pop $11)       ; $11 = color
+    (pop $0)        ; $0 = click_x
+    (pop $1)        ; $1 = click_y
+    (pop $2)        ; $2 = box_x
+    (pop $3)        ; $3 = box_y
+    (pop $5)        ; $5 = box_size
+
+    ; Compute right = box_x + box_size
+    (add-int $6 $2 $5)    ; $6 = right edge
+    
+    ; Compute bottom = box_y + box_size  
+    (add-int $7 $3 $5)    ; $7 = bottom edge
+
+    ; Check 1: click_x >= box_x ?
+    (jump-ge-int &check2 $0 $2)
+    (return)
+
+    (label check2)
+    ; Check 2: click_x <= right ?
+    (jump-le-int &check3 $0 $6)
+    (return)
+
+    (label check3)
+    ; Check 3: click_y >= box_y ?
+    (jump-ge-int &check4 $1 $3)
+    (return)
+
+    (label check4)
+    ; Check 4: click_y <= bottom ?
+    (jump-le-int &check5 $1 $7)
+    (return)
+
+    (label check5) ; if it was selected then set the color
+    (load-immediate $13 1)
+    (jump-eq-int &set-color $12 $13)
+    (return)    
+
+    (label set-color)
+    (load-immediate $10 &SELECTED-COLOR)
+    (store-8 $10 $11)
+    (return))
+
   (label draw-outlined-swatch
     (pop $3)   ; y
     (pop $2)   ; x
@@ -207,6 +360,7 @@
 (data
 	(label screen-namespace "/dev/screen/0")
   (label mouse-namespace "/dev/mouse/0")
+  (label SELECTED-COLOR 255)
 	(label BLACK 0)
 	(label WHITE 255)
 	(label CHARCOAL 36)