mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-12-25 20:30:31 +00:00
81 lines
1.3 KiB
ArmAsm
81 lines
1.3 KiB
ArmAsm
;clear_screens:
|
|
; ;===================================
|
|
; ; Clear top/bottom of page 0
|
|
; ;===================================
|
|
;
|
|
; lda #$0
|
|
; sta DRAW_PAGE
|
|
; jsr clear_top
|
|
; jsr clear_bottom
|
|
|
|
; ;===================================
|
|
; ; Clear top/bottom of page 1
|
|
; ;===================================
|
|
;
|
|
; lda #$4
|
|
; sta DRAW_PAGE
|
|
; jsr clear_top
|
|
; jsr clear_bottom
|
|
;
|
|
; rts
|
|
|
|
;clear_bottoms:
|
|
|
|
; lda DRAW_PAGE
|
|
; pha
|
|
|
|
;===================================
|
|
; Clear bottom of page 0
|
|
;===================================
|
|
|
|
; lda #$0
|
|
; sta DRAW_PAGE
|
|
; jsr clear_bottom
|
|
|
|
;===================================
|
|
; Clear bottom of page 1
|
|
;===================================
|
|
|
|
; lda #$4
|
|
; sta DRAW_PAGE
|
|
; jsr clear_bottom
|
|
|
|
; pla
|
|
; sta DRAW_PAGE
|
|
|
|
; rts
|
|
|
|
;=========================================================
|
|
; clear_bottom
|
|
;=========================================================
|
|
; clear bottom of draw page
|
|
|
|
clear_bottom:
|
|
clc ; 2
|
|
lda DRAW_PAGE ; 3
|
|
|
|
adc #6 ; 2
|
|
sta __cbf2+2 ; 3
|
|
sta __cbf2+5 ; 3
|
|
adc #1 ; 2
|
|
sta __cbf2+8 ; 3
|
|
sta __cbf2+11 ; 3
|
|
|
|
|
|
ldy #120 ; 2
|
|
lda #$a0 ; Normal Space ; 2
|
|
clear_bottom_fast_loop:
|
|
__cbf2:
|
|
sta $600,Y ; 5
|
|
sta $680,Y ; 5
|
|
sta $700,Y ; 5
|
|
sta $780,Y ; 5
|
|
|
|
dey ; 2
|
|
cpy #80 ; 2
|
|
bpl clear_bottom_fast_loop ; 2nt/3
|
|
|
|
rts ; 6
|
|
|
|
|