anchor.diff:      member val VBlankClear = (vBlankSet + 28) % rasterLinesPerFrame
       member val RasterLinesPerFrame = rasterLinesPerFrame
       member val RasterOpsX = 0x15C - ((65 - cyclesPerRasterLine) * 8)
  +    member val MaxRasterX = System.Math.Min(64, cyclesPerRasterLine) * 8
   
   type Vic2State(config:Vic2Configuration) = 
  -    // Constants
  -    let bitMasks = [0x01; 0x02; 0x04; 0x08; 0x10; 0x20; 0x40; 0x80]
  -
       // MnX (00, 02, 04, 06, 08, 0A, 0C, 0E, 10)
       let mobX = [|0;0;0;0;0;0;0;0|]
       let GetLowMobX (index:int) =
  
positive.code:         (if rowSelect then 0x08 else 0x00) |||
          yScroll
      let SetControlRegister1 (value:int) =
          SetHighRasterYCompareValue(value) |> ignore
          extraColorMode <- (value &&& 0x40 <> 0x00)
          bitmapMode <- (value &&& 0x20 <> 0x00)
          displayEnabled <- (value &&& 0x10 <> 0x00)
  
negative.code:     let SetLowRasterYCompareValue (value:int) =
          rasterYCompareValue <- (rasterYCompareValue &&& 0x100) ||| value
          value
  
      // Control register 1 (11) (RST8/ECM/BMM/DEN/RSEL/YSCROLL)
      let mutable extraColorMode = false
  