         @spPatternTableAddress = (value  << 9) & 0x1000 # C[3] -> 0x0000 / 0x1000
         @bgPatternTableAddress = (value  << 8) & 0x1000 # C[4] -> 0x0000 / 0x1000
         @bigSprites            = (value >>> 5) & 1      # C[5]
-        @vblankGeneratesNMI    = (value >>> 7)          # C[7]
+        @nmiEnabled            = (value >>> 7)          # C[7]
 
     ###########################################################
     # Mask register

        @vblankStarted = 1
        @vblankActive = 1
        @frameAvailable = true
        @cpu.activateInterrupt Interrupt.NMI if @vblankGeneratesNMI

    leaveVBlank: ->
        @vblankStarted = 0
        @vblankActive = 0
        @spriteZeroHit = 0

    incrementCycle: ->
        @cycle++

        @$updateScrolling() if @$isRenderingActive()
        @$updateVBlank()
        @$incrementCycle()
        @$generateDelayedNMI() if @delayedNMI

    isRenderingCycle: ->
        0 <= @scanline <= 239 and 1 <= @cycle <= 256
