anchor.diff:      let SetLowRasterYCompareValue (value:int) =
           rasterYCompareValue <- (rasterYCompareValue &&& 0x100) ||| value
           value
  -    let SetHighRasterYCompareValue (value:int) =
  -        rasterYCompareValue <- (rasterYCompareValue &&& 0x0FF) ||| ((value &&& 0x80) <<< 1)
  -        value
   
       // Control register 1 (11) (RST8/ECM/BMM/DEN/RSEL/YSCROLL)
       let mutable extraColorMode = false
  
positive.code: 
      // Display/Idle state
      let mutable displayState = false
  
      let GoToDisplayState () =
          displayState <- true
          displayState
  
negative.code:         (if rowSelect then 0x08 else 0x00) |||
          yScroll
      let SetControlRegister1 (value:int) =
          rasterYCompareValue <- (rasterYCompareValue &&& 0x0FF) ||| ((value &&& 0x80) <<< 1)
          extraColorMode <- (value &&& 0x40 <> 0x00)
          bitmapMode <- (value &&& 0x20 <> 0x00)
          displayEnabled <- (value &&& 0x10 <> 0x00)
  