"Rotate"
By Robert Newman
ARCADIAN 6, no. 11/12  (October 31, 1984): 116.


From the Arcadian:


"ROTATE" is a sort of 2-D Cube plus "15-puzzle," where scrambled letters have 
to be placed in alphabetical order by rotating a 2x2 square segment within the 
total board.

Rotate a 2x2 square by keying in the letter in the upper-left hand corner of 
that square, and so put the whole board in order.  One special move will 
interchange two horizontally adjacent letters at each reset if you enter "3", 
then the left letter of the pair.  Reset by entering "R".  Correct a wrong 
rotation with "T".  Quit with "Q".  Keypad entry for each move of answer, 
reenter game after seeing part of answer by "t" key, or "GO" key for full 
speed.  "LEVEL" equals approximate difficulty.

We have a lengthy description of the operation of this game, what the computer 
is doing, etc., which we will send to you, on receipt of a long stamped, self-
addressed envelope (LSSAE) (Robert Fabris).


The material that Bob is referring to is among the "Bob Fabris Collection,"
and it has been scanned in.  It is certainly worth a look.  Bob sent the
additional paperwork to someone named Al with a note that said, "See anything
interesting?"  Al replied, "This looks like an interesting and challenging 
game.  Mr. Newman spent a lot of effort in describing the game and how the 
program works.  This is something most authors fail to do adequately. It also 
appears that he has made efficient use of the Bally's limited memory."


Below are the complete directions taken from Robert Newman's complete nine-page 
program listing and description.  Note, that there is still PLENTY more by 
looking at the original listing sent to the "Arcadian," as it describes in 
GREAT detail exactly how the program works.  It may be the most detailed
AstroBASIC listing and description ever sent to the "Arcadian."


ROTATE

A 4x4 playing board contains the letters A-P in scrambled order.   A group of 
letters in a 2x2 square on the board is rotated one position clockwise by 
keying in the letter in the upper left corner of the square.   The object is to 
put the board in alphabetic order (ABCD) on the top row, etc. in as few moves 
as possible.   In addition to rotating groups of letters you have one special 
move which will interchange a pair of horizontally adjacent letters.   To make 
a special move, enter "S", then the left letter of the pair.   If you're a 
fumble fingers like me and accidentally rotate a letter you didn't want to, 
enter "T" and the square will continue to rotate until it returns to its former 
position.   To restore the board to its original setup before any moves were 
made, enter "R" (for Reset).   With each reset you get one special move.   To 
quit, enter "Q".   The difficulty of any given puzzle corresponds roughly to 
the level D which is input by the player.

Some of you may have seen "Rotate" on other systems, or in a book of computer 
games.   No originality is claimed for the basic idea, rotating groups of 
letters on a 4x4 board.   What DOES seem to be original in this version is the 
way the computer randomizes the board by rotating the letters in its memory in 
a direction opposite to that of a player trying to reorder the board.   Once 
this randomizing scheme was hit upon (a case of serendipity, to be sure), it 
was obvious that if the computer took D counterclockwise rotations to randomize 
the board, it should be possible for the player to reorder the board with D 
clockwise rotations (if he is smart enough, anyway).   Since D can be specified 
by the player, the level of difficulty can be selected according to the 
player's ability or mood.   Since the computer stored each of its moves as it 
randomized the board, its answer is available for display.   After first 
restoring the board to its original setup, the computer changes it accordingly 
as it prints each move until the board is in proper alphabetic order.   Since 
the computer can make its moves quite rapidly.   I have it wait for a keypad 
input, before each move except the first, so that each move can be studied at 
one's leisure.   To get back into the game, press the divide key, or press the 
"GO" key to have the computer print out the rest of the answer at full speed.

Regular Moves

Regular moves are specified by keying in the letter occupying the upper left 
corner of a 2x2 square.  Each of the letters in the square then rotates one 
position clockwise.  Nothing will happen if an attempt is made to key in a 
letter in the bottom row or rightmost column.

Special Moves

A special move interchanging: two horizontally adjacent letters is accomplished 
by entering "S" and then the left letter of the pair to be interchanged.  If an 
attempt is made to enter a letter in the right-hand column, the entry of the 
previous "S" is nullified.  If a "T" entry immediately follows an "S" entry, 
the "T" is acted upon, and the "S" is also nullified.  One special move is 
allowed during the initial game and each reset.  After a special move is made, 
a message appears indicating such.  Once this message appears, and provided 
that there are no intervening resets, any further "S" entries will be ignored 
and the following entry treated as a regular move.
 
Resets

If the player thinks of a better strategy, or would otherwise like to start 
over again, an entry of "R" will restore the board to its original setup.  A 
player may reset as often as desired; the reset itself does not count as a 
move.  After each reset a message will appear indicating how many resets have 
been made and the TOTAL number of moves up to the current reset.  "MOVE # XX?" 
is asking for move number XX of the current reset.  The computer also resets 
the board to display its answer, and this will be reflected in the reset count.  
Finally, the computer resets the board when "N" is entered in response to "NEW 
GAME? (Y/N)", but in this case there is no reset message.

"T" (Try Again) Entries

If you should inadvertently rotate a letter you did not mean to rotate, input a 
"T" and the letters will continue to rotate until they come to their previous 
position.  Note that the move counter is also changed accordingly, so that you 
are not charged for your mistake.  "T" entries are ignored unless a regular 
move has just been made.  Multiple "T" entries are also ignored.

Quitting

You may quit by entering a "Q".  One of the messages which will appear after a 
"Q" entry is "ANSWER? (Y/N)".  A "Y" response to this message will cause the 
computer to reset the board, display and make the first move, and wait for a 
keypad input.  Any keypad input other than "GO" or divide sign will cause the 
computer to display and make the next move, and wait for another input.  By 
pressing the divide key you may reenter the game.  If you do not reenter the 
game the program will reset the board and ask "NEW GAME? (Y/N)" after the last 
stored move is displayed.  If the "GO" key is pressed the computer will display 
its stored answer at full speed without waiting for further input (hence no 
opportunity to try the current puzzle again except as a new player).  A "N" 
response to "ANSWER? (Y/N)" will cause the program to go immediately to "NEW 
GAME (Y/N)", with consequent resetting of the board.

Additional Notes

Answering "N" to "NEW GAME? (Y/N)" resets the board and all relevant variables 
(except as noted below), and allows a new player a fresh start on the same 
puzzle after someone else has given up.  Answering "Y" starts the program over 
and requests a new difficulty level.

If 10 moves of a level 15 puzzle have been displayed, obviously what remains is 
no longer a level 15 puzzle, but a level 5.  A reverse box to the left of the 
board shows how many moves the computer has revealed, if any.  This will 
continue to be displayed, with the new colors that appear when the answer is 
asked for, even if a new player tries to solve the same puzzle, since they may 
have also seen the solution and it would otherwise be too easy to cheat.

If you reenter the game by pressing the divide key, you may notice that the 
moves the computer made are charged to you.  Nothing is free these days.

As noted before, the level is only an approximate indication of the difficulty 
of a puzzle.  For example, some level 3's may be more difficult than some (very 
few) level 5's.  Also, beyond a certain point which I have never bothered to 
pin down, but which I think is somewhere in the 20's, the higher the level, the 
easier it is to get the "WOW! SMARTY!" message which appears when you take 
fewer moves to solve the puzzle than the computer did to set it up.  In any 
case, it is more challenging to get this message if you do not make a special 
move.

There are a variety of messages that come up when you solve the puzzle.  I 
think these are fairly self-explanatory.  "ME" refers to the computer as it 
tells you how many more or fewer moves it took you to solve the puzzle than the 
computer took to set the puzzle up (the difference between the number of your 
moves and the difficulty level).

The system that I saw "Rotate" on and which gave me the basic idea of rotating 
groups of letters took approximately 6800 bytes, and did no more than give 
direction, set up a random board, perform and keep count of regular and special 
moves, and print messages saying how many moves you made before emitting or 
winning.  There were no solutions, no resets, no error corrections, et cetera.  
I no longer have access to that system, and never did study the listing to see 
where all that memory was going, but find myself wishing that Bally had even 
half as much.  Maybe then we could afford to waste a few bytes too.

"Rotation" lends itself to endless variations - let me know of any possible 
improvements you might hit upon.  I would also be very interested to know what 
is the lowest level you are able to get the "WOW! SMARTY!" message on, both 
with and without special moves.  It would be especially interesting if anyone 
could beat the same puzzle both ways.  How many regular moves (and which?) 
would be equivalent to one special move?

Running the Program

In order to save memory, all variables are not cleared at the beginning of the 
program.  However, key variables are cleared later at appropriate places.  This 
should cause no problem provided the machine is reset prior to inputting the 
program, and provided that a "Q" entry is used rather than the halt button when 
a new puzzle is desired in the midst of a game


The documentation that is provided with "Rotate" goes on in great length, but 
the rest does not describe how to play the game.