Revision History

* V1.02 1 June 1996

  Added timing diagrams for ULA external signals (memory/bus, video) derived
  from measured signals. Replaces old Figure 1.

  Modified control/sequencer description to match actual signal timing.

  Included flowchart of ULA operation for above description

  Changed Text/Gfx selector behaviour. Now hires mode is forcibly ended at
  line 200 (as far as generation goes, character lookup still depends on
  selector).

  Improved handling around 6 bit shift register/inverse bit.

  Added control and sequencing logic diagram. Removed blanking from C&S (not
  used in real design), added some implied control signals (clocks and
  enables)

  Tidied up names of signals to be more consistent across sheets

* V1.01 20 May 1996

  Corrected operation of inverse bit in pixel data.

  Reset attributes to no flash/standard/single height/paper 0/ink 7 at the
  start of each scanline.

* V1.00 18 May 1996

  Initial Release.