Tetrad7 Documentation:

Tetrad7 is a Tetris-like game 
written for the Atari Porfolio that 
allows you to choose the keys used 
to control the pieces, and also the 
direction the pieces fall. (towards 
the left or right edge)

If you start Tetrad7 without any 
'command line arguments', the game 
begins with the pieces falling to 
the left end of the screen, and the 
following key assignments for moving 
the pieces: Left - "W" or "7", Right 
- "Z" or "9", Spin - "S" or "8", and 
Drop - "A" or the spacebar.  Almost 
all the keys on the keyboard can be 
reassigned for these four functions, 
with the exception of 'Esc', 'Lock', 
'/|\' (the 'Atari Key'), 'Fn', 
'Ctrl', 'Alt', and the shift keys.

EXAMPLE: If you want to use the 'E', 
'D', and 'C' keys for left, spin, 
and right, and the '1' key for drop, 
you would enter:

	tetrad7 e d c 1

followed by a carriage return.  The 
symbols for the keys assigned then 
appear on the game display.

Please note that the key order on 
the command line is 'left, spin, 
right, and drop', that there is a 
space between each letter, that 
letters can be entered in either 
upper- or lower-case, and that all 
four keys must be reassigned at the 
same time.  To clarify the last 
point, if you want to use '2' for 
Left, and leave 'S', 'Z' and 'A' as 
they are, you would still have to 
enter:

	tetrad7 2 s z a

To get Tetrad7 to drop the pieces to 
the right end, you add the letter 
'r' after the 4 key reassignments.  
For example, if you want to use '.', 
'L', 'O' and 'D', and have the 
pieces fall to the right, you would 
enter

	tetrad7 . l o d r

The added 'r' (either upper- or 
lower-case) would cause the pieces 
to fall to the right.  

Some keys, such as the spacebar and 
arrow keys, can be assigned by 
entering their assigned symbol.  
Tetrad7 will list the keys and 
symbols if you enter tetrad7 and any 
single letter on the command line.  
The available keys and their symbols 
are: 

Backspace : '{' (left curly bracket)
Del Key   : '#'
Enter Key : '!'
Spacebar  : '_' (underbar)
Quote Key : '`' (accent symbol)
Tab Key   : '+'
Up Arrow  : '^'
Down Arrow: '|' (vertical bar)
Left Arrow: '(' (left paren)
Right Arrow: ')'(right paren)

For example, if you want to use the 
left and right arrow keys for left 
and right, the up key for spin, the 
down key for drop, and the pieces 
falling to the left end, you would 
enter

	tetrad7 ( ^ ) |

Once you have found your ideal 
combination of control keys and drop 
direction, you can create a batch 
file with that command line in it, 
so that you won't have to retype the 
line every time.

Playing Tetrad7

Tetrad7 is very similar to the game 
Tetris in the way it is played.  
After starting Tetrad7, you are 
prompted for a starting level.  
Level 0 is impossibly slow, while 
level 9 is equally impossibly fast.  
After selecting a level, the screen 
will clear to the game area.  At the 
'top' (opposite the drop direction) 
the score, key assignments, and a 
preview box is displayed.  The rest 
of the screen consists of a well or 
pit into which one of seven types of 
four-block figures (tetrads) will 
fall.  The game won't actually start 
until you press a key, to give you 
time to position your fingers.  
Pieces fall from the top toward the 
bottom of the pit,  The object is to 
position the pieces so that they 
create solid rows, which will then 
disappear.  As you continue to 
complete rows, the level of play 
will increase, which increases the 
value of the falling pieces, as well 
as the speed with which they fall.  
The game is over when no more pieces 
can be dropped from the top because 
of being blocked.  

At the top of the screen is a 
preview box which will display the 
next piece that will be dropped.  
You can cause the game to pause by 
pressing the Esc key.  To resume, 
press any other key.  If you wish to 
end the game press Esc again.  There 
is a rudimentary sound feature.  If 
you have the game paused and press 
the letter 's', the computer will 
beep every time a level is 
completed.  If after turning the 
sound on you decide you don't want 
it, pause the game again and press 
's' again to toggle the sound off.

Screen Mode:
For best results, the external 
screen mode should be set to 
'normal'.  The program will function 
correctly in 'static' mode (not 
'tracked'), but the end of the game 
won't redisplay the DOS prompt.

About Tetrad7

Tetrad7 was written in C for the 
Atari Portfolio computer.  The 
source code was compiled using the 
Datalight Optimum-C compiler, then 
compressed using the public domain 
utility Lzexe.  

Tetrad7 is released to the public 
domain for private non-commercial 
use and enjoyment.

Tetrad7 (c) 1990 James Casstevens

Atari and Portfolio are trademarks 
of Atari Corporation
Tetris is a trademark of Academy 
Soft-ELORG.
Lzexe (c) Fabrice Bellard
Optimum-C is a trademark of 
Datalight

Thanks to Frank and Natalie for
beta-testing.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               