$D030/53296/VIC+48:  C128 only: Switch to FAST-Mode

   +----------+---------------------------------------------------+
   | Bits 7-2 |   no Function, always 1                           |
   | Bit  1   |   1 = Test-Mode(?)                                |
   |          |       ($D012 increases by one per cycle)          |
   | Bit  0   |   1 = Enable 2 MHz-Mode, VIC displays whatever is |
   |          |       on data-bus when in visible area            |
   +----------+---------------------------------------------------+