59 lines
769 B
ArmAsm
59 lines
769 B
ArmAsm
;=======================
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; HGR2 Clearscreen
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;=======================
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; note, using BKGND0 for this takes 0x44198 = 278,936 cycles
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; unrolled here takes 0x0A501 = 42,241 cycles
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hgr2:
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bit SET_GR
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bit HIRES
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bit PAGE2
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lda #$40
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sta HGR_PAGE
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lda #$00
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hgr2_clearscreen:
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before:
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ldy #0
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hgr_cls_loop:
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sta $2000,Y
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sta $2100,Y
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sta $2200,Y
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sta $2300,Y
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sta $2400,Y
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sta $2500,Y
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sta $2600,Y
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sta $2700,Y
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sta $2800,Y
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sta $2900,Y
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sta $2A00,Y
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sta $2B00,Y
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sta $2C00,Y
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sta $2D00,Y
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sta $2E00,Y
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sta $2F00,Y
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sta $3000,Y
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sta $3100,Y
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sta $3200,Y
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sta $3300,Y
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sta $3400,Y
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sta $3500,Y
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sta $3600,Y
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sta $3700,Y
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sta $3800,Y
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sta $3900,Y
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sta $3A00,Y
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sta $3B00,Y
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sta $3C00,Y
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sta $3D00,Y
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sta $3E00,Y
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sta $3F00,Y
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iny
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bne hgr_cls_loop
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after:
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rts
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