     div_timer_step(cycles);
 
     // STEP -> GPU
-    let vblank_begin = gpu_step(cycles);
-
-    if vblank_begin {
+    let vblank = gpu_step(cycles);
+
+    if vblank {
       // Rasterize framebuffer
       gpu_present();
 

  // Sprite Attribute Table (OAM): $FE00 – $FE9F
  if (address >= 0xFE00) and (address <= 0xFE9F) {
    // OAM cannot be accessed in modes 2 or 3
    let mode = mmu_read8(0xFF41) & 3;
    if mode == 3 or mode == 2 { return 0xFF; }

    return *(oam + (address & 0xFF));
  }

  // Video RAM: $8000 – $9FFF
  if (address & 0xF000) <= 0x9000 {
    // FIXME: VRAM cannot be accessed in mode 3
    // let mode = mmu_read8(0xFF41) & 3;
    // if gpu_lcd_enable and mode == 3 { return; }

    // GPU VRAM
    *(vram + (address & 0x1FFF)) = value;
