mirror of
https://github.com/deater/dos33fsprogs.git
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80 lines
914 B
ArmAsm
80 lines
914 B
ArmAsm
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;=======================================
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; scrolls to PAGE1
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; relies on going off the edge...
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;=======================================
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hgr_vertical_scroll:
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ldx #0
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outer_vscroll_loop:
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lda hposn_low,X
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sta OUTL
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lda hposn_high,X
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sta OUTH
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txa
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clc
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adc #8
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tay
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lda hposn_low,y
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sta INL
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lda hposn_high,Y
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sta INH
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ldy #29
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inner_vscroll_loop:
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lda (INL),Y
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sta (OUTL),Y
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dey
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cpy #9
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bpl inner_vscroll_loop
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inx
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cpx #184
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bne outer_vscroll_loop
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;================================
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; copy in off screen
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; for now from 0..19
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hgr_vertical_scroll2:
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ldx #184
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outer_vscroll_loop2:
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lda hposn_low,X
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clc
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adc #10
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sta OUTL
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lda hposn_high,X
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sta OUTH
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ldy COUNT
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lda hposn_low,Y
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sta INL
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lda hposn_high,Y
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clc
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adc #$40 ; load from $6000
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sta INH
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ldy #19
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inner_vscroll_loop2:
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lda (INL),Y
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sta (OUTL),Y
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dey
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bpl inner_vscroll_loop2
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inc COUNT
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inx
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cpx #192
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bne outer_vscroll_loop2
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rts
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