mirror of
https://github.com/deater/dos33fsprogs.git
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71 lines
1.1 KiB
ArmAsm
71 lines
1.1 KiB
ArmAsm
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.include "zp.inc"
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;================================
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; Clear screen and setup graphics
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;================================
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jsr clear_screens ; clear top/bottom of page 0/1
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jsr set_gr_page0
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;===============
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; Init Variables
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;===============
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lda #0
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sta DISP_PAGE
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scroll_loop:
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ldx scroll_length
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ldy #0
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draw_loop:
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lda scroll_row1,Y
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sta $400,Y
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lda scroll_row2,Y
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sta $480,Y
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lda scroll_row3,Y
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sta $500,Y
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lda scroll_row4,Y
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sta $580,Y
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iny
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dex
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bne draw_loop
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;==================
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; flip pages
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;==================
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; jsr page_flip ; 6
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;==================
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; loop forever
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;==================
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jmp scroll_loop ; 3
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;===============================================
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; External modules
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;===============================================
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.include "utils.s"
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;===============================================
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; Variables
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;===============================================
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.include "deater_scroll.inc"
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; waste memory with a lookup table
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; move this to the zeropage?
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gr_offsets:
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.word $400,$480,$500,$580,$600,$680,$700,$780
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.word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
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.word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0
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