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⌂ ∞ Elite on the BBC Micro and NES

Dashboard: ABORT2

[NES version, Bank 0]

       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 active 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 pattern number for the new missile indicator:

                          * 133 = no missile indicator

                          * 109 = red (armed and locked)

                          * 108 = black (disarmed)

                        The armed missile flashes black and red, so the tile is
                        swapped between 108 and 109 in the main loop



.ABORT2

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

 SETUP_PPU_FOR_ICON_BAR ; If the PPU has started drawing the icon bar, configure
                        ; the PPU to use nametable 0 and pattern table 0

 LDX NOMSL              ; Call MSBAR to update the active indicator in the
 JSR MSBAR              ; dashboard's missile bar, which returns with Y = 0

 JMP UpdateIconBar_b3   ; Update the icon bar so the missile button shows the
                        ; correct available option for the active missile,
                        ; returning from the subroutine using a tail call

.msbpars

 EQUB 4, 0, 0, 0, 0     ; These bytes appear to be unused (they are left over
                        ; from the 6502 Second Processor version of Elite)