50 lines
714 B
NASM
50 lines
714 B
NASM
|
; A very simple SNES init routine
|
||
|
|
; For serious use, you probably want to do more than this
|
||
|
|
; This is simple and understandable, though
|
||
|
|
; Will leave you in A8 XY16 mode
|
||
|
|
|
||
|
|
; Disable interrupts and enable native (i.e. not 6502-emulating) mode
|
||
|
|
sei
|
||
|
|
clc
|
||
|
|
xce
|
||
|
|
cld
|
||
|
|
|
||
|
|
setAXY16
|
||
|
|
|
||
|
|
; ZeroCPU registers NMITIMEN through MEMSEL
|
||
|
|
stz $4200
|
||
|
|
stz $4202
|
||
|
|
stz $4204
|
||
|
|
stz $4206
|
||
|
|
stz $4208
|
||
|
|
stz $420A
|
||
|
|
stz $420C
|
||
|
|
|
||
|
|
lda #$0080
|
||
|
|
sta INIDISP ; Turn off screen ("forced blank")
|
||
|
|
|
||
|
|
; Zero some registers used for rendering
|
||
|
|
stz OAMADDL
|
||
|
|
stz BGMODE
|
||
|
|
stz BG1SC
|
||
|
|
stz BG3SC
|
||
|
|
stz BG12NBA
|
||
|
|
stz VMADDL
|
||
|
|
stz W12SEL
|
||
|
|
stz WH0
|
||
|
|
stz WH2
|
||
|
|
stz WBGLOG
|
||
|
|
stz TM
|
||
|
|
stz TMW
|
||
|
|
|
||
|
|
; Disable color math / etc
|
||
|
|
ldx #$0030
|
||
|
|
stx CGWSEL
|
||
|
|
ldy #$00E0
|
||
|
|
sty COLDATA
|
||
|
|
|
||
|
|
setA8
|
||
|
|
|
||
|
|
; Zero window masks
|
||
|
|
stz WOBJSEL
|