dos33fsprogs/games/peasant/hgr_hgr2.s

60 lines
781 B
ArmAsm
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;=======================
; HGR2 Clearscreen
;=======================
; note, using BKGND0 for this takes 0x44198 = 278,936 cycles
; unrolled here takes 0x0A501 = 42,241 cycles
hgr2:
bit PAGE2
bit FULLGR
lda #$40
sta HGR_PAGE
lda HIRES
lda SET_GR
lda #$00
hgr2_clearscreen:
before:
ldy #0
hgr_cls_loop:
sta $4000,Y
sta $4100,Y
sta $4200,Y
sta $4300,Y
sta $4400,Y
sta $4500,Y
sta $4600,Y
sta $4700,Y
sta $4800,Y
sta $4900,Y
sta $4A00,Y
sta $4B00,Y
sta $4C00,Y
sta $4D00,Y
sta $4E00,Y
sta $4F00,Y
sta $5000,Y
sta $5100,Y
sta $5200,Y
sta $5300,Y
sta $5400,Y
sta $5500,Y
sta $5600,Y
sta $5700,Y
sta $5800,Y
sta $5900,Y
sta $5A00,Y
sta $5B00,Y
sta $5C00,Y
sta $5D00,Y
sta $5E00,Y
sta $5F00,Y
iny
bne hgr_cls_loop
after:
rts