Read from joypad

homebrew-tutorial/main.asm

@@ -85,6 +85,20 @@ start:
     sta VMDATAL
     stz VMDATAH
 
+    ; Show bg1
+    lda #%00000001
+    sta TM
+
+    lda #$0f
+    sta INIDISP
+
+    lda #$01
+    sta NMITIMEN
+
+mainloop:
+    lda JOY1H
+    bit #%00000100 ; Down button
+    beq down_not_pressed
         ; write tile 2 to position (4, 8)
         TILE_X2= 4
         TILE_Y2= 8
@@ -93,14 +107,9 @@ start:
         lda #$02
         sta VMDATAL
         stz VMDATAH
+    down_not_pressed:
 
-    ; Show bg1
-    lda #%00000001
-    sta TM
-
-
-    lda #$0f
-    sta INIDISP
+    bra mainloop
 
 busywait:
     bra busywait