45 lines
711 B
ArmAsm
45 lines
711 B
ArmAsm
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chrout_screen_advance_to_next_line:
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// Go to start of line
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lda #0
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sta PNTR
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// Advance line number
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ldy TBLX
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// Do quick fix to line pointer to work out if it is off
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// the bottom of the screen.
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ldx #40
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lda LDTBL,y
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bmi !+
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.byte $2c
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!: ldx #80
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txa
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clc
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adc PNT+0
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sta PNT+0
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lda PNT+1
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adc #0
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sta PNT+1
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inc TBLX
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// Check if it will trigger scrolling
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// Work out if we have gone off the bottom of the screen?
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// 1040 > 1024, so if high byte of screen pointer is >= (HIBASE+4),
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// then we are off the bottom of the screen
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lda PNT+1
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sec
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sbc HIBASE
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cmp #3
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bcc !+
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lda PNT+0
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cmp #$e7
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bcc !+
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// Off the bottom of the screen
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jsr scroll_screen_up
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!:
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jmp chrout_screen_calc_lptr_done
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