Square Mess

solution

Yellow


The 9 by 9 grid of characters represents the memory of a simple computer. (The numbers at top and left are not part of the memory; they merely indicate the indexing system.) In addition, the computer has four registers X, Y, DX, DY, which are all initialized to zero. The computer repeats the following process until encountering the stop code:

1. Print the character at memory location (X,Y).
2. Perform the operation indicated by memory location (X,Y).
3. Replace X by X + DX and Y by Y + DY (modulo 9).

Each character (letter or space) represents a different operation from the following table. An operation (other than "stop", which terminates execution) consists of applying the specified rule simultaneously to DX and DY; for instance, if DX and DY have the values 2 and 3, and the operation is to replace DX by -DX-DY and DY by DX, then the new values of DX and DY will be -5 and 2.

Your task is to determine which character stands for which operation. If you do this correctly, the output of the computer will provide further instructions. Some more things to keep in mind:

New value of DXNew value of DY
DX+1DY
DX-1DY
DXDY+1
DXDY-1
DX+1DY+1
DX+1DY-1
DX-1DY+1
DX-1DY-1
-DXDY
DX-DY
DYDX
-DYDX
DY-DX
-DY-DX
DX+1-DY
DX-1-DY
-DXDY+1
-DXDY-1
stopstop

     x-->
   012345678
  0FM  ETY O
  1IHIGLM DN
y 2SGLHRAE T
| 3SITAWK AE
| 4 YUOREO R
V 5LGRANFAHH
  6NY LAFSRW
  7FHMAETR U
  8GIT ET LW