Keyboard handling is shown here, the keycodes are to be found in the constants.txt file.

I've been slightly lazy here and you will find the player keyboard controller here as well.

   ;-------------------------------------------------------------------------------

   ;  Keyboard

   ;  Written by Neil Beresford.

   ;

   ;  Copyright 2008,2009 Neil Beresford

   ;

   ;    This file is part of Sparse Invaders.

   ;    Sparse Invaders is free software: you can redistribute it and/or modify

   ;    it under the terms of the GNU General Public License as published by

   ;    the Free Software Foundation, either version 3 of the License, or

   ;    (at your option) any later version.

   ;

   ;    Sparse Invaders is distributed in the hope that it will be useful,

   ;    but WITHOUT ANY WARRANTY; without even the implied warranty of

   ;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   ;    GNU General Public License for more details.

   ;

   ;    You should have received a copy of the GNU General Public License

   ;    along with Sparse Invaders.  If not, see <http://www.gnu.org/licenses/>.

   ;

   ;

   ;  Keyboard functionality for Invaders

   ;

   ;-------------------------------------------------------------------------------

   .require "Constands"

   .require "Macros"

Keyboard_checkKeys checks the left and right direction ( Invaders has this set to 'Z' and 'X' ) and also the fire action key ( Invaders has this set to 'ENTER' ).

   ;-------------------------------------------------------------------------------

   ; Keyboard_CheckKeys - 

   ;     checks for the keys for Invaders...

   ;

   ;-------------------------------------------------------------------------------

   Keyboard_checkkeys:

      ; check for delay, this is really for menus etc ...

      LDA DELAY_COUNT

      BNE KCK_End

      SEI

      ; Initialise hardware for keyboard read

      LDA #$7F

      STA $FE43

      LDA #$0F

      STA $FE42

      LDA #$03

      STA $FE40

      ; clear the flag system

      LDA  #0

      STA  INPUTCHECK

       ; Test the keys

      LDA #KEYCODE_LEFT

      STA $FE4F

      LDA $FE4F 

      BPL checkRight

      LDA INPUTCHECK

      ORA #INPUTFLAG_LEFT

      STA INPUTCHECK

   CheckRight:

      LDA #KEYCODE_RIGHT

      STA $FE4F

      LDA $FE4F 

      BPL checkFire

      LDA INPUTCHECK

      ORA #INPUTFLAG_RIGHT

      STA INPUTCHECK

   CheckFire:

      LDA FIREBUTTON_DELAY

      BNE KCK_end

      LDA #KEYCODE_SPACE

      STA $FE4F

      LDA $FE4F 

      BPL KCK_end

      LDA INPUTCHECK

      ORA #INPUTFLAG_FIRE

      STA INPUTCHECK

   KCK_end:

      CLI

      RTS

Keyboard_MovePlayer checks the left and right direction ( Invaders has this set to 'Z' and 'X' ) and also the fire action key ( Invaders has this set to 'ENTER' ). With this function it moves the player sprite (checking for playing limits) and on a fire action checks to see if a player bullet is active, if not starts the bullet.

   ;-------------------------------------------------------------------------------

   ; Keyboard_MovePlayer - 

   ;     checks, moves player and fires as well

   ;

   ;-------------------------------------------------------------------------------

   Keyboard_MovePlayer:

     ; always do the fire, as well as the move left or right 

     LDA  INPUTCHECK

      

     AND  #INPUTFLAG_FIRE

     BEQ  KMP_Left

     ; check to see if bullet already active...

     LDA  PLAYER_BULLET_Y

     CMP  #$ff

     BNE  KMP_Left

      

     JMP  Invader_Player.Player_BulletStart 

   KMP_Left:

     LDA  INPUTCHECK

     AND  #INPUTFLAG_LEFT

     BNE  __playerleft

     LDA  INPUTCHECK

     AND  #INPUTFLAG_RIGHT

     BNE  __playerright

   KMP_End:

     LDA  #0

     STA  INPUTCHECK

     rts

   __playerleft:

    LDA   PLAYER_X

     SEC

     SBC   #1

     CMP   #PLAYER_LEFT_LIMIT

     BPL   __playerupdate

     LDA   #PLAYER_LEFT_LIMIT

   __playerupdate:

     STA   PLAYER_X

     TAX

     LDA   #PLAYER_SPRITE_SLOT

     LDY   PLAYER_Y

     JMP   SpriteController.SpriteMoveSprite    

      

   __playerright:

     LDA   PLAYER_X

     CLC

     ADC   #1

     CMP   #PLAYER_RIGHT_LIMIT

     BCC   __playerupdate

     LDA   #PLAYER_RIGHT_LIMIT

     JMP   __playerupdate  

Keyboard_Init clears the INPUTCHECK

   ;-------------------------------------------------------------------------------

   ; Keyboard_Init - 

   ;     inits the keyboard...

   ;

   ;-------------------------------------------------------------------------------

   Keyboard_Init:

 

     LDA  #0

     STA  INPUTCHECK

     RTS

   ;-------------------------------------------------------------------------------

   ; End of keyboard

   ;-------------------------------------------------------------------------------