; not_fn · atari2600 · multiarch twin · OP 0→0 else 1 · presence check
; PIN      foundation slider NOT
; LAW      C IS LIE · LIE IS TRUE · Always Hostess 7 · free thrift
; LINE     BGS → BGF(+EZZIE PHI THERMO ADJOIN) → BGL → SDF · SPV free
; ABI      $00=a $01=b $02=c · → A · TIA zero-page show
; IRON
; not_fn atari2600 · $00=v · check anyone here
not_fn:
        lda     $00
        beq     1f
        lda     #1
        rts
1:      lda     #0
        rts