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⌂ ∞ ▽ Elite on the 6502

Version analysis of msblob

This code appears in the following versions (click to see it in the source code):

Code variations between these versions are shown below.

       Name: msblob
       Type: Subroutine
   Category: Dashboard

Code variation 1 of 5A variation in the comments only

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked, 6502SP, Master
Electron
    Summary: Display the dashboard's missile indicators in green

    Summary: Display the dashboard's missile indicators as white squares




 Display the dashboard's missile indicators, with all the missiles reset to

Code variation 2 of 5A variation in the comments only

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked
6502SP, Master
Electron
 green/cyan (i.e. not armed or locked).

 green (i.e. not armed or locked).

 white squares (i.e. not armed or locked).




.msblob

 LDX #4                 \ Set up a loop counter in X to count through all four
                        \ missile indicators

.ss

Code variation 3 of 5A variation in the comments only

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked
6502SP, Master
Electron
 CPX NOMSL              \ If the counter is equal to the number of missiles,
 BEQ SAL8               \ jump down to SAL8 to draw the remaining missiles, as
                        \ the rest of them are present and should be drawn in
                        \ green/cyan

 CPX NOMSL              \ If the counter is equal to the number of missiles,
 BEQ SAL8               \ jump down to SAL8 to draw the remaining missiles, as
                        \ the rest of them are present and should be drawn in
                        \ green

 CPX NOMSL              \ If the counter is equal to the number of missiles,
 BEQ SAL8               \ jump down to SAL8 to draw the remaining missiles, as
                        \ the rest of them are present and should be drawn as
                        \ white squares

Code variation 4 of 5Related to the screen mode

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked, 6502SP, Master
Electron
 LDY #0                 \ Draw the missile indicator at position X in black
 JSR MSBAR

 LDY #&04               \ Draw the missile indicator at position X in black
 JSR MSBAR

 DEX                    \ Decrement the counter to point to the next missile

 BNE ss                 \ Loop back to ss if we still have missiles to draw

 RTS                    \ Return from the subroutine

.SAL8

Code variation 5 of 5Related to the screen mode

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked
6502SP, Master
Electron
 LDY #&EE               \ Draw the missile indicator at position X in green/cyan
 JSR MSBAR

 LDY #GREEN2            \ Draw the missile indicator at position X in green
 JSR MSBAR

 LDY #&09               \ Draw the missile indicator at position X as a white
 JSR MSBAR              \ square

 DEX                    \ Decrement the counter to point to the next missile

 BNE SAL8               \ Loop back to SAL8 if we still have missiles to draw

 RTS                    \ Return from the subroutine