Skip to navigation

⌂ ∞ ▽ Elite on the BBC Micro and NES

Dashboard: ABORT2

[Elite-A, Parasite]

       Name: ABORT2                                                  [Show more]
       Type: Subroutine
   Category: Dashboard
    Summary: Set/unset the lock target for a missile and update the dashboard

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * Main flight loop (Part 11 of 16) calls ABORT2




 Set the lock target for the leftmost missile and update the dashboard.



 Arguments:

   X                    The slot number of the ship to lock our missile onto, or
                        &FF to remove missile lock

   Y                    The new colour of the missile indicator:

                          * &00 = black (no missile)

                          * &0E = red (armed and locked)

                          * &E0 = yellow/white (armed)

                          * &EE = green/cyan (disarmed)



.ABORT2

 STX MSTG               \ Store the target of our missile lock in MSTG

 LDX NOMSL              \ Call MSBAR (via MSBARS) to update the leftmost
 DEX                    \ indicator in the dashboard's missile bar, by calling
 JSR MSBARS             \ with X = NOMSL - 1 (as the missile indicators are
                        \ numbered 0-3 in Elite-A rather than the 1-4 in the
                        \ disc version)
                        \
                        \ MSBARS returns with Y = 0

 STY MSAR               \ Set MSAR = 0 to indicate that the leftmost missile
                        \ is no longer seeking a target lock

 RTS                    \ Return from the subroutine