Missions: PAS1

       Name: PAS1                                                    [Show more]
       Type: Subroutine
   Category: Missions
    Summary: Display a rotating ship at space coordinates (0, 112, 256) and
             scan the keyboard
    Context: See this subroutine in context in the source code
 Variations: See code variations for this subroutine in the different versions
 References: This subroutine is called as follows:
             * PAUSE calls PAS1


 Returns:

   X                    If a key is being pressed, X contains the internal key
                        number, otherwise it contains 0

   A                    Contains the same as X


.PAS1

 LDA #112               \ Set y_lo = 112
 STA INWK+3

 LDA #0                 \ Set x_lo = 0
 STA INWK

 STA INWK+6             \ Set z_lo = 0

 LDA #2                 \ Set z_hi = 1, so (z_hi z_lo) = 256
 STA INWK+7

 JSR LL9                \ Draw the ship on screen

 JSR MVEIT              \ Call MVEIT to move and rotate the ship in space

 JMP RDKEY              \ Scan the keyboard for a key press and return the
                        \ internal key number in X (or 0 for no key press),
                        \ returning from the subroutine using a tail call