mirror of
https://github.com/safiire/n65.git
synced 2024-12-12 00:29:03 +00:00
25 lines
526 B
NASM
25 lines
526 B
NASM
; Create an iNES header
|
|
.ines {"prog": 1, "char": 0, "mapper": 0, "mirror": 1}
|
|
|
|
; Here is the start of our code
|
|
.org $C000
|
|
start:
|
|
LDA #$01 ; square 1
|
|
STA $4015
|
|
LDA #$08 ; period low
|
|
STA $4002
|
|
LDA #$02 ; period high
|
|
STA $4003
|
|
LDA #$BF ; volume
|
|
STA $4000
|
|
forever:
|
|
JMP forever
|
|
|
|
nmi:
|
|
RTI
|
|
|
|
.org $FFFA ; Here are the three interrupt vectors
|
|
.dw nmi ; VBlank non-maskable interrupt
|
|
.dw start ; When the processor is reset or powers on
|
|
.dw $0 ; External interrupt IRQ
|