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⌂ ∞ Elite on the BBC Micro and NES

Flight: ESCAPE

[Acorn Electron version]

       Name: ESCAPE                                                  [Show more]
       Type: Subroutine
   Category: Flight
    Summary: Launch our escape pod

    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:
             * Main flight loop (Part 3 of 16) calls ESCAPE




 This routine displays our doomed Cobra Mk III disappearing off into the ether
 before arranging our replacement ship. Called when we press ESCAPE during
 flight and have an escape pod fitted.



.ESCAPE

 JSR RES2               \ Reset a number of flight variables and workspaces

.ESL1

 JSR RESET              \ Call RESET to reset our ship and various controls

 LDA #0                 \ Set A = 0 so we can use it to zero the contents of
                        \ the cargo hold

 LDX #16                \ We lose all our cargo when using our escape pod, so
                        \ up a counter in X so we can zero the 17 cargo slots
                        \ in QQ20

.ESL2

 STA QQ20,X             \ Set the X-th byte of QQ20 to zero (as we know A = 0
                        \ from the BEQ above), so we no longer have any of item
                        \ type X in the cargo hold

 DEX                    \ Decrement the counter

 BPL ESL2               \ Loop back to ESL2 until we have emptied the entire
                        \ cargo hold

 STA FIST               \ Launching an escape pod also clears our criminal
                        \ record, so set our legal status in FIST to 0 ("clean")

 STA ESCP               \ The escape pod is a one-use item, so set ESCP to 0 so
                        \ we no longer have one fitted

 LDA #70                \ Our replacement ship is delivered with a full tank of
 STA QQ14               \ fuel, so set the current fuel level in QQ14 to 70, or
                        \ 7.0 light years

 JMP BAY                \ Go to the docking bay (i.e. show the Status Mode
                        \ screen) and return from the subroutine with a tail
                        \ call