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88 lines
2.1 KiB
ArmAsm
88 lines
2.1 KiB
ArmAsm
.constructor initconio, 24
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.import vdc_init
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.import psg_init
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.import colors
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.import _pce_font
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.importzp ptr1, tmp1
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.include "pce.inc"
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.include "extzp.inc"
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.segment "ONCE"
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initconio:
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jsr vdc_init
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jsr psg_init
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jsr load_font
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set_palette:
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stz VCE_ADDR_LO
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stz VCE_ADDR_HI
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clx
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@lp: ldy #16 ; size of a palette
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@lp1: lda colors,x
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sta VCE_DATA_LO
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lda colors+1,x
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sta VCE_DATA_HI
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dey
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bne @lp1
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inx
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inx
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cpx #16 * 2 ; 16 palettes
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bne @lp
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sty BGCOLOR ; white on black
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iny
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sty CHARCOLOR
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VREG VDC_CR, $0088 ; enable background and vertical-blank interrupt
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rts
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; Load the conio font into the VDC.
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load_font:
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VREG VDC_MAWR, $2000
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st0 #VDC_VWR
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stz tmp1 ; #%00000000
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bsr copy ; make normal characters
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dec tmp1 ; #%11111111
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; bsr copy ; make reversed characters
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; rts ; (fall through)
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; Point to the font data.
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copy: lda #<_pce_font
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ldx #>_pce_font
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sta ptr1
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stx ptr1+1
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ldy #$80 ; 128 chars
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charloop:
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ldx #$08 ; 8 bytes/char
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lineloop:
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lda (ptr1)
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eor tmp1
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sta VDC_DATA_LO ; bitplane 0
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st2 #>$0000 ; bitplane 1
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inc ptr1 ; increment font pointer
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bne @noC
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inc ptr1+1
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@noC: dex
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bne lineloop ; next bitplane-0 byte
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ldx #$08 ; fill bitplanes 2 and 3 with 0
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fillloop:
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st1 #<$0000
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st2 #>$0000
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dex
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bne fillloop ; next byte
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dey
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bne charloop ; next character
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rts
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