This is the routine to leave the program              
3399 REM ****** Quit ******     !                               
3400 INPUT ;: PRINT OVER 1;AT 2 !Check the validity of the      
,16;"        ": GO SUB Coff: PR !intent to leave.               
NT #1;"Are you sure you want to !                               
quit?": GO SUB 400: IF NOT (q$= !                               
y" OR q$="Y") THEN RETURN       !                               
3410 CLS : PRINT " This program !                               
will self-destructbut the chara !                               
ters will remain  intact in mem !                               
ory."                           !                               
3420 PRINT ''" To turn the char !                               
cters on, you use"' PAPER 2'"   !Print out a farewell message   
POKE 23606,0: POKE 23607,";ch;" !and instructions to turn on the
"'"  POKE 23676,";CH+4;": POKE  !characters.                    
3675,88",                       !                               
3430 PRINT '" To turn the chara !                               
ters off, youuse"' PAPER 2'"    !                               
OKE 23606,0: POKE 23607,60  "   !                               
3440 PRINT ''" Press a key, and !                               
this program            will";  !                               
LASH 1;" NEW "                  !                               
3450 PRINT '"            Bye!!" !                               
3460 PAUSE 0: PAUSE 0: PAUSE 0  !Wait for a key, then remove    
3470 NEW                        !program.                       
================================================================
      This is the other diagonal reflection routine. The        
         explanation is with the other routine.                 
3499 REM ********Spin \******** !                               
3500 PRINT OVER 1;AT 6,20;"     !Highlight the function name.   
 "                              !                               
3505 FOR q=0 TO 6: FOR w=0 TO 6 !Reflect.                       
q                               !                               
3510 LET dog=POINT (96+q,24+w): !                               
PLOT INVERSE NOT POINT (103-w,3 !                               
-q);96+q,24+w                   !                               
3520 PLOT INVERSE NOT dog;103-w !                               
31-q                            !                               
3530 NEXT w: NEXT q             !                               
3550 PRINT OVER 1;AT 6,20;"     !Remove the highlighting.       
 "                              !                               
3560 RETURN                     !And return.                    
================================================================
         This routine superimposes one character ontop of the   
             one already on the grid.                           
 For the XOR part, the routine uses PRINT OVER 1; which prints  
 by doing XOR. For the OR part, the routine goes through every  
 pixel on the left grid and ORs it with the appropriate one on  
3599 REM *****Superimpose*****  !                               
3600 PRINT OVER 1;AT 13,20;"    !Highlight the function name.   
       "                        !                               
3610 GO SUB 300                 !Get the character.             
3620 GO SUB coff: PRINT AT 21,0 !Select XOR or OR.              
"  XOR  or  OR ...?  (X/O)"     !                               
3625 GO SUB 400: IF q$="O" THEN !Get the key-press and go to the
GO TO 3650                      !appropriate part.              
3630 IF q$<>"X" THEN GO TO 3770 !                               
3633 REM ******** XOR ********* !                               
3635 PRINT OVER 1;AT 21,2;"   " !Highlight 'XOR'.               
3640 OVER 1: GO SUB 1500: OVER  !Print the character on top of  
                                !the small grid using OVER 1.   
3645 GOTO 3770                  !Jump forward to exit the       
                                !routine.                       
3649 REM ******** OR *********  !                               
3650 PRINT OVER 1;AT 21,11;"  " !Highlight 'OR'.                
3660 PRINT AT 18,13;: GO SUB 15 !Print the character next to the
5                               !small grid.                    
3670 FOR Q=0 TO 7: FOR W=0 TO 7 !Loop round for each row and    
                                !each line.                     
3680 PLOT INVERSE NOT (POINT (9 !Take each pixel and OR it with 
+W,24+Q) OR POINT (104+W,24+Q)) !the other grid.                
96+W,24+Q                       !                               
3690 NEXT W: NEXT Q             !Loop back.                     
3700 PRINT AT 18,13;" "         !Remove the second grid.        
3770 PRINT OVER 1;AT 13,20;"    !Remove the highlighting.       
       "                        !                               
3780 PRINT AT 21,0;"            !                               
                 "              !                               
3790 RETURN                     !And return.                    
================================================================