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⌂ ∞ ▽ Elite on the 6502

Version analysis of VEC

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

Code variations between these versions are shown below.

Code variation 1 of 2A variation in the comments only

This variation is blank in the 6502 Second Processor version.

Cassette, Flight, Master
       Name: VEC
       Type: Variable
   Category: Drawing the screen
    Summary: The original value of the IRQ1 vector

.VEC

Code variation 2 of 2Minor and very low-impact

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

Cassette, 6502SP
Flight
Master
 SKIP 2                 \ VEC = &7FFE
                        \
                        \ This gets set to the value of the original IRQ1 vector
                        \ by the loading process

IF _STH_DISC OR _IB_DISC

 EQUW &0004             \ VEC = &7FFE
                        \
                        \ This gets set to the value of the original IRQ1 vector
                        \ by the loading process
                        \
                        \ This default value is random workspace noise left over
                        \ from the BBC Micro assembly process; it gets
                        \ overwritten

ELIF _SRAM_DISC

 SKIP 2                 \ VEC = &7FFE
                        \
                        \ This gets set to the value of the original IRQ1 vector
                        \ by the loading process

ENDIF

 EQUW &8888             \ This gets set to the value of the original IRQ1 vector
                        \ by the STARTUP routine