Update of PCE Tetris demo

From David Shadoff <xxxxxx@interlog.com>
Date
I have a small update of the PCE Tetris demo.

http://www.interlog.com/~daves/pce_dev/game.html

New features include:
- line erasure when lines are full
- pieces drop from above the play area
- end-game detection if piece is transferred into the "piece-drop" area,
instead of the playing field.
- some minor graphic changes
- fix a couple of small bugs with piece transfer

I hope to get real-time piece-drop happening soon, and perhaps even scoring.

Stay tuned.