mirror of https://github.com/stella-emu/stella.git
136 lines
1.2 KiB
NASM
136 lines
1.2 KiB
NASM
|
;;A bankswitching demo for the F8SC scheme. 2 4K banks of ROM + 128 bytes of RAM
|
||
|
|
;;By: Rick Skrbina 3/29/09
|
||
|
|
|
||
|
|
processor 6502
|
||
|
|
include "vcs.h"
|
||
|
|
include "macro.h"
|
||
|
|
|
||
|
|
PF_Color_Read equ PF_Color_Write+128
|
||
|
|
seg.u vars
|
||
|
|
org $80
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
seg.u SC_RAM_vars
|
||
|
|
org $1000
|
||
|
|
PF_Color_Write ds 1
|
||
|
|
|
||
|
|
seg Bank_0
|
||
|
|
|
||
|
|
org $E000
|
||
|
|
rorg $F000
|
||
|
|
|
||
|
|
repeat 256
|
||
|
|
.byte $00
|
||
|
|
repend
|
||
|
|
|
||
|
|
Start_0
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
|
||
|
|
CLEAN_START
|
||
|
|
; jsr Call_1
|
||
|
|
lda #$FF
|
||
|
|
sta PF1
|
||
|
|
StartFrame
|
||
|
|
lda #2
|
||
|
|
sta VBLANK
|
||
|
|
sta VSYNC
|
||
|
|
|
||
|
|
sta WSYNC
|
||
|
|
sta WSYNC
|
||
|
|
sta WSYNC
|
||
|
|
|
||
|
|
lda #0
|
||
|
|
sta VSYNC
|
||
|
|
|
||
|
|
ldy #37
|
||
|
|
Vert
|
||
|
|
sta WSYNC
|
||
|
|
dey
|
||
|
|
bne Vert
|
||
|
|
|
||
|
|
lda #0
|
||
|
|
sta VBLANK
|
||
|
|
|
||
|
|
ldy #192
|
||
|
|
Pic
|
||
|
|
sta WSYNC
|
||
|
|
dey
|
||
|
|
bne Pic
|
||
|
|
|
||
|
|
lda #2
|
||
|
|
sta VBLANK
|
||
|
|
|
||
|
|
ldy #30
|
||
|
|
Over
|
||
|
|
sta WSYNC
|
||
|
|
dey
|
||
|
|
bne Over
|
||
|
|
|
||
|
|
jsr Call_1
|
||
|
|
|
||
|
|
lda PF_Color_Read
|
||
|
|
sta COLUPF
|
||
|
|
|
||
|
|
|
||
|
|
jmp StartFrame
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
org $EFE0
|
||
|
|
rorg $FFE0
|
||
|
|
Call_1
|
||
|
|
stx $FFF9
|
||
|
|
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
nop
|
||
|
|
|
||
|
|
rts
|
||
|
|
|
||
|
|
org $EFF8
|
||
|
|
rorg $FFF8
|
||
|
|
.word $FFFF
|
||
|
|
.word Start_0
|
||
|
|
.word Start_0
|
||
|
|
.word Start_0
|
||
|
|
|
||
|
|
seg Bank_1
|
||
|
|
|
||
|
|
org $F000
|
||
|
|
rorg $F000
|
||
|
|
|
||
|
|
repeat 256
|
||
|
|
.byte $00
|
||
|
|
repend
|
||
|
|
|
||
|
|
Init_1
|
||
|
|
sta $FFF8
|
||
|
|
Bank1_Sub
|
||
|
|
; lda #$0F
|
||
|
|
; sta COLUPF
|
||
|
|
; inc PF_Color
|
||
|
|
clc
|
||
|
|
lda PF_Color_Read
|
||
|
|
adc #1
|
||
|
|
sta PF_Color_Write
|
||
|
|
rts
|
||
|
|
|
||
|
|
org $FFE3
|
||
|
|
rorg $FFE3
|
||
|
|
jsr Bank1_Sub
|
||
|
|
stx $FFF8
|
||
|
|
|
||
|
|
org $FFF8
|
||
|
|
.word $FFFF
|
||
|
|
.word Init_1
|
||
|
|
.word Init_1
|
||
|
|
.word Init_1
|
||
|
|
|