mirror of
https://github.com/cc65/cc65.git
synced 2024-10-31 20:06:11 +00:00
33 lines
857 B
ArmAsm
33 lines
857 B
ArmAsm
.export vdc_init
|
|
|
|
.include "pce.inc"
|
|
|
|
; FIXME: implement selection of different video modes at runtime
|
|
HIRES = 1
|
|
|
|
vdc_init:
|
|
lda VDC_CTRL
|
|
|
|
VREG VDC_CR , $0000 ; disable display and interrupts
|
|
VREG VDC_BXR, $0000 ; no scrolling
|
|
VREG VDC_BYR, $0000
|
|
VREG VDC_MWR, $0070 ; 128 x 64 tiles (1024 x 512 pixels)
|
|
VREG VDC_VSR, $1702 ; CRTC
|
|
VREG VDC_VDR, $00DF ; CRTC - VDS
|
|
VREG VDC_VCR, $000C ; CRTC - VDE
|
|
VREG VDC_DCR, $0000
|
|
|
|
.if HIRES
|
|
VREG VDC_HSR, $0C02 ; CRTC
|
|
VREG VDC_HDR, $043C ; CRTC - HDS
|
|
lda #$06
|
|
.else
|
|
VREG VDC_HSR, $0202 ; CRTC
|
|
VREG VDC_HDR, $041F ; CRTC - HDS
|
|
lda #$04
|
|
.endif
|
|
sta VCE_CTRL
|
|
|
|
lda VDC_CTRL
|
|
rts
|