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⌂ ∞ Elite on the BBC Micro and NES

Keyboard: PAUSE2

[Elite-A, Encyclopedia]

       Name: PAUSE2                                                  [Show more]
       Type: Subroutine
   Category: Keyboard
    Summary: Wait until a key is pressed, ignoring any existing key press

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * trading calls PAUSE2




 Returns:

   X                    The internal key number of the key that was pressed



.PAUSE2

 JSR RDKEY              \ Scan the keyboard for a key press and return the
                        \ internal key number in X (or 0 for no key press)

 BNE PAUSE2             \ If a key was already being held down when we entered
                        \ this routine, keep looping back up to PAUSE2, until
                        \ the key is released

                        \ --- Mod: Code added for Elite-A: -------------------->

.l_out

                        \ --- End of added code ------------------------------->

 JSR RDKEY              \ Any pre-existing key press is now gone, so we can
                        \ start scanning the keyboard again, returning the
                        \ internal key number in X (or 0 for no key press)

                        \ --- Mod: Code removed for Elite-A: ------------------>

\ BEQ PAUSE2            \ Keep looping up to PAUSE2 until a key is pressed

                        \ --- And replaced by: -------------------------------->

 BEQ l_out              \ Keep looping up to l_out until a key is pressed

                        \ --- End of replacement ------------------------------>

 RTS                    \ Return from the subroutine