Dashboard: MSBAR

       Name: MSBAR                                                   [Show more]
       Type: Subroutine
   Category: Dashboard
    Summary: Draw a specific indicator in the dashboard's missile bar by
             sending a put_missle command to the I/O processor
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * MSBARS calls MSBAR
             * msblob calls MSBAR


 Arguments:

   X                    The number of the missile indicator to update (counting
                        from right to left and starting at 0 rather than 1, so
                        indicator NOMSL - 1 is the leftmost indicator)

   Y                    The colour of the missile indicator:

                          * &00 = black (no missile)

                          * &0E = red (armed and locked)

                          * &E0 = yellow/white (armed)

                          * &EE = green/cyan (disarmed)


 Returns:

   X                    X is preserved

   Y                    Y is set to 0


.MSBAR

 LDA #&88               \ Send command &86 to the I/O processor:
 JSR tube_write         \
                        \   put_missle(number, colour)
                        \
                        \ which will update missile indicator with the specified
                        \ number, changing it to the specified colour

 TXA                    \ Send the first parameter to the I/O processor:
 JSR tube_write         \
                        \   * number = X

 TYA                    \ Send the second parameter to the I/O processor:
 JSR tube_write         \
                        \   * colour = Y

 LDY #0                 \ Set Y = 0 to ensure we return the same value as the
                        \ SCAN routine in the non-Tube version

 RTS                    \ Return from the subroutine