dos33fsprogs/vertical_scroll/gr_copy.s

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2020-02-17 18:41:01 +00:00
;=========================================================
; gr_copy_to_current, 40x48 version
;=========================================================
; copy 0xc00 to DRAW_PAGE
;
; 45 + 2 + 120*(8*9 + 5) -1 + 6 = 9292
;.align $100
gr_copy_to_current:
lda DRAW_PAGE ; 3
clc ; 2
adc #$4 ; 2
sta gr_copy_line+5 ; 4
sta gr_copy_line+11 ; 4
adc #$1 ; 2
sta gr_copy_line+17 ; 4
sta gr_copy_line+23 ; 4
adc #$1 ; 2
sta gr_copy_line+29 ; 4
sta gr_copy_line+35 ; 4
adc #$1 ; 2
sta gr_copy_line+41 ; 4
sta gr_copy_line+47 ; 4
;===========
; 45
ldy #119 ; for early ones, copy 120 bytes ; 2
gr_copy_line:
lda $C00,Y ; load a byte (self modified) ; 4
sta $400,Y ; store a byte (self modified) ; 5
lda $C80,Y ; load a byte (self modified) ; 4
sta $480,Y ; store a byte (self modified) ; 5
lda $D00,Y ; load a byte (self modified) ; 4
sta $500,Y ; store a byte (self modified) ; 5
lda $D80,Y ; load a byte (self modified) ; 4
sta $580,Y ; store a byte (self modified) ; 5
lda $E00,Y ; load a byte (self modified) ; 4
sta $600,Y ; store a byte (self modified) ; 5
lda $E80,Y ; load a byte (self modified) ; 4
sta $680,Y ; store a byte (self modified) ; 5
lda $F00,Y ; load a byte (self modified) ; 4
sta $700,Y ; store a byte (self modified) ; 5
lda $F80,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
;=========================================================
; gr_copy_to_current, 40x48 version
;=========================================================
; copy 0x1000 to DRAW_PAGE
gr_copy_to_current_1000:
lda DRAW_PAGE ; 3
clc ; 2
adc #$4 ; 2
sta gr_copy_line_40+5 ; 4
sta gr_copy_line_40+11 ; 4
adc #$1 ; 2
sta gr_copy_line_40+17 ; 4
sta gr_copy_line_40+23 ; 4
adc #$1 ; 2
sta gr_copy_line_40+29 ; 4
sta gr_copy_line_40+35 ; 4
adc #$1 ; 2
sta gr_copy_line_40+41 ; 4
sta gr_copy_line_40+47 ; 4
;===========
; 45
ldy #119 ; for early ones, copy 120 bytes ; 2
gr_copy_line_40:
lda $1000,Y ; load a byte (self modified) ; 4
sta $400,Y ; store a byte (self modified) ; 5
lda $1080,Y ; load a byte (self modified) ; 4
sta $480,Y ; store a byte (self modified) ; 5
lda $1100,Y ; load a byte (self modified) ; 4
sta $500,Y ; store a byte (self modified) ; 5
lda $1180,Y ; load a byte (self modified) ; 4
sta $580,Y ; store a byte (self modified) ; 5
lda $1200,Y ; load a byte (self modified) ; 4
sta $600,Y ; store a byte (self modified) ; 5
lda $1280,Y ; load a byte (self modified) ; 4
sta $680,Y ; store a byte (self modified) ; 5
lda $1300,Y ; load a byte (self modified) ; 4
sta $700,Y ; store a byte (self modified) ; 5
lda $1380,Y ; load a byte (self modified) ; 4
sta $780,Y ; store a byte (self modified) ; 5
dey ; decrement pointer ; 2
bpl gr_copy_line_40 ; ; 2nt/3
rts ; 6
;=========================================================
; gr_copy_to_current_40x40
;=========================================================
; Take image in 0xc00
; Copy to DRAW_PAGE
; Actually copy lines 0..39
; Don't over-write bottom 4 lines of text
gr_copy_to_current_40x40:
ldx #0
gc_40x40_loop:
lda gr_offsets,x
sta OUTL
sta INL
lda gr_offsets+1,x
clc
adc DRAW_PAGE
sta OUTH
lda gr_offsets+1,x
clc
adc #$8
sta INH
ldy #39
gc_40x40_inner:
lda (INL),Y
sta (OUTL),Y
dey
bpl gc_40x40_inner
inx
inx
cpx #40
bne gc_40x40_loop
rts ; 6