build address table at runtime

This commit is contained in:
4am 2020-09-06 15:47:47 -04:00
parent 9dafce5ae8
commit 5d8c483073

View File

@ -5,6 +5,16 @@
!to "build/FX/DHGR.FIZZLE",plain !to "build/FX/DHGR.FIZZLE",plain
*=$6000 *=$6000
addrs=$6100
ldx #$1F ; build address lookup table
- txa
eor #$20
sta addrs, x
eor #$80
sta addrs+$20, x
dex
bpl -
ldx #(end-start) ; copy LFSR code to zero page ldx #(end-start) ; copy LFSR code to zero page
- lda start-1, x - lda start-1, x
sta $0, x sta $0, x
@ -51,8 +61,3 @@ exit lda $4000 ; last lousy byte (because LFSR never hits
rts rts
} }
end end
addrs
!byte $20,$21,$22,$23,$24,$25,$26,$27,$28,$29,$2A,$2B,$2C,$2D,$2E,$2F
!byte $30,$31,$32,$33,$34,$35,$36,$37,$38,$39,$3A,$3B,$3C,$3D,$3E,$3F
!byte $A0,$A1,$A2,$A3,$A4,$A5,$A6,$A7,$A8,$A9,$AA,$AB,$AC,$AD,$AE,$AF
!byte $B0,$B1,$B2,$B3,$B4,$B5,$B6,$B7,$B8,$B9,$BA,$BB,$BC,$BD,$BE,$BF