dos33fsprogs/games/peasant/gr_copy.s
2021-08-24 13:38:03 -04:00

40 lines
1.1 KiB
ArmAsm

;=========================================================
; gr_copy_to_page1, 40x48 version
;=========================================================
; copy $2000 to $400, careful to avoid screen holes
gr_copy_to_page1:
ldy #119 ; for early ones, copy 120 bytes ; 2
gr_copy_line:
lda $2000,Y ; load a byte (self modified) ; 4
sta $400,Y ; store a byte (self modified) ; 5
lda $2080,Y ; load a byte (self modified) ; 4
sta $480,Y ; store a byte (self modified) ; 5
lda $2100,Y ; load a byte (self modified) ; 4
sta $500,Y ; store a byte (self modified) ; 5
lda $2180,Y ; load a byte (self modified) ; 4
sta $580,Y ; store a byte (self modified) ; 5
lda $2200,Y ; load a byte (self modified) ; 4
sta $600,Y ; store a byte (self modified) ; 5
lda $2280,Y ; load a byte (self modified) ; 4
sta $680,Y ; store a byte (self modified) ; 5
lda $2300,Y ; load a byte (self modified) ; 4
sta $700,Y ; store a byte (self modified) ; 5
lda $2380,Y ; load a byte (self modified) ; 4
sta $780,Y ; store a byte (self modified) ; 5
dey ; decrement pointer ; 2
bpl gr_copy_line ; ; 2nt/3
rts ; 6