Apple-2-SW/apple2_hgr_font_tutorial
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Add asciitable asm source

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Michaelangel007 2016-01-27 23:26:52 -08:00
parent 5e8239fbb4
commit 2c15cf46f9
1 changed files with 60 additions and 0 deletions
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asm/asciitable.s Normal file
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__MAIN = $1080
.include "dos33.inc"
.include "ca65.inc"
KEYBOARD = $C000
KEYSTROBE = $C010
TXTCLR = $C050 ; Mode Graphics
MIXCLR = $C052 ; Full screen
MIXSET = $C053 ; Split screen
PAGE1 = $C054
HIRES = $C057 ; Mode HGR
HgrLo = $F5
HgrHi = $F6
glyph = $FE
DrawChar = $310
HgrLoY = $3A0
HgrHiY = $3B8
AsciiTable
BIT PAGE1 ; Page 1
BIT TXTCLR ; not text, but graphics
BIT MIXSET ; Split screen text/graphics
BIT HIRES ; HGR, no GR
LDA #0 ; glyph=0
STA glyph ; save which glyph to draw
LDY #8 ; Row=8
_RowN
LDA HgrLoY,Y
STA HgrLo ; Screen Address Lo
LDA HgrHiY,Y
ORA #$20 ; HGR Page 1
STA HgrHi ; Screen Address Hi
LDY #00 ; Y = col
_Glyph
LDA glyph ; A = glyph
JSR DrawChar
INC glyph ; yes, ++glyph
LDA glyph ;
CMP #$20 ; done 16 chars?
BEQ _Row1
CMP #$40
BEQ _Row2
CMP #$60
BEQ _Row3
CMP #$80
BNE _Glyph ;
_Done RTS ; Optimization: BEQ _Row4
_Row1 LDY #9
BNE _RowN
_Row2 LDY #10
BNE _RowN
_Row3 LDY #11
BNE _RowN
__END: