Extra Rheolism  -  A one-line Tetris game

by Olly Betts

Extra Rheolism is an amazing fully-working Tetris game in just one line of Basic. Based on an earlier one-line game called Rheolism by David Moore and Martin Hollis, Olly Betts' enhanced version features colourful pieces, scoring, left, right, rotate and drop keyboard controls, editable speed and a game over message. The program is listed in this month's RISC User magazine.

The game is contained within a Command file which is executed when you run the item from the RISC User menu system or double-click on the !XtraRheol icon in a directory viewer. This clears the screen, puts the machine into Basic and tests to see if your monitor can display mode 9. If you see the figure "9" on the screen, you can then type RUN to start the game. If you see any other number, the game will not work correctly on your system. To get back to the desktop after the game has finished, enter QUIT.

Playing the game
The aim of Tetris is, of course, to manipulate the falling pieces so that they form complete rows at the bottom of the play area. Once a row is complete and contains no gaps, it vanishes. The game ends when the play area has filled up to the top, and this results in the Basic error message "Mistake" (rather unsophisticated but it is a one-line program!).

Extra Rheolism features multiple key-sets, but the easiest keys to use are the following:
	Keypad 4: move piece left
	Keypad 6: move piece right
	Keypad 5: rotate piece
	Shift: drop piece to the bottom

Scoring is based on how far a piece falls; the closer to the bottom it gets, the higher the score. If you find the game too fast, the speed can be altered by editing the number 6 in line 4; the higher the number, the slower the game, with a value of 99 being the highest allowed.

Copyright  RISC User 1996
