Tetris 89 0.71
--------------
6/15/99

Ported from Ti-92 by Joel Jordan
Original version Tetris 1.21 by Jimmy Mrdell

This is, essentially, a nice, clean rip of Jimmy Mrdell's excellent Tetris 92.  
It's been majorly improved since the first release, and now everything in the original
version seems to work fine.

Version 0.71 is just a recompile for current version of PlusShell and DoorsOS.
I couldn't believe no one had done this yet, so I decided to. (jdratlif@indiana.edu)

/=====================\
|  What's new in .70  |
\=====================/
    TWO PLAYER MODE!

Things that work
----------------
o 1 player mode
o High score table
o Teacher Key (HOME key)
o All normal Keys should work
o Title Screen
o Level/Rows Select
o Two Player mode
o Graphics Data "fixed"

Things that don't work
----------------------
Well, you tell me... Currently, I need people to test the two player mode for me,
though the code is barely modified from the original 92 version and it should therefore
work fine.  I have only tested it with my 89 and 85 at this point, and it gave me no
problems.  Whether or not problems might appear with other calcs I do not know.
	
Required libs
-------------
	UTIL
	GRAY4LIB

Keys
----
Up 	Rotate Piece
2nd     Rotate Piece
Shift   Rotate Piece other way
Down	Move the piece faster downwards
Left	Move the piece left
Right	Move the piece right
Diamond Move the piece all the way down
alpha	Pause
ESC	Exit
HOME    Teacher Key


Other stuff
-----------
In order to fit the whole thing onto the screen, I had to shrink the blocks (actually,
it just doesn't display the last two lines).  Perhaps this can be rewritten a little to
make the blocks look a little more correct.

This finally got put up on Ticalc.org, but I'm leaving it anyway.

First, write key read mask to memory location $600018.  Then, wait about 16 nops worth of
time and read from memory location $60001B.  This will tell you which keys in the selected
row(s) are turned on or off.  Here's the breakdown for you:

         Key bit read
Mask bit|  0   |  1   |  2   |  3   |  4   |  5   |  6    |   7   |   
------------------------------------------------------------------
    0   |  Up  | Left | Down | Right| 2nd  |shift |diamond| alpha |
-------------------------------------------------------------------
    1   |Enter |  +   |  -   |  *   |  /   |  ^   | clear |  F5   |
-------------------------------------------------------------------
    2   |  (-) |  3   |  6   |  9   |  ,   |  T   | <--   |  F4   |
------------------------------------------------------------------
    3   |  .   |  2   |  5   |  8   |  )   |  Z   |catalog|  F3   |
-------------------------------------------------------------------
    4   |  0   |  1   |  4   |  7   |  (   |  Y   | Mode  |  F2   |
-------------------------------------------------------------------
    5   | Apps |Sto-> |  EE  |  |   |  =   |  X   | Home  |  F1   |
-------------------------------------------------------------------
    6   | ESC  |
-------------------------------------------------------------------
   
History
-------

Version         Date            Comments
=======         ====            ========
0.50            10/15/98        It works!  More than that, I can't say

0.60            10/16/98        Fixed title screen, level select, keys mapped
                                correctly, High score table

0.61            10/25/98        Changed keys around a bit.

0.70		11/1/98 	Added two player support.
				Graphics data fixed (no clipping
				at bottom of sprites)

0.71		6/15/99		No big change. Just recompiled for current
				versions of PlusShell and DoorsOS

Other than that, enjoy!

Questions, comments, etc.
<scriber@usa.net>
-Joel Jordan

