NeoGeo Development Wiki

https://wiki.neogeodev.org/index.php
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A comprehensive technical documentation resource for the SNK NeoGeo hardware platforms, covering...
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### Set Data Format Command Examples

Source: https://wiki.neogeodev.org/index.php?action=edit&title=MESS_OUT

Examples demonstrating how to configure data reading as bytes or words with either end codes or defined lengths.

```asm
dc.w $0001,$15FF ;Data will be read in bytes, upper byte will always be $15, end code is $FF.
dc.w $0101,$1520 ;Data will be read in bytes, upper byte will always be $15, data length is $20.
dc.w $0201,$8000 ;Data will be read in words, end code is $8000.
dc.w $0301,$2044 ;Data will be read in words, data length is $2044.
```

--------------------------------

### HOW_TO_PLAY Example Command List (NAM-1975)

Source: https://wiki.neogeodev.org/index.php?action=edit&title=HOW_TO_PLAY

An example of a HOW_TO_PLAY command list used in the game NAM-1975, demonstrating various command types and their parameters.

```APIDOC
## HOW_TO_PLAY Example Command List (NAM-1975)

### Example
```
0000 0200 ; All buttons released
0000 01FF ; All arrows highlighted
0010 F3E2 ; MESS_OUT write "NAM 1975" "CONTROL HERO AND CURSOR"
0004 ; Wait 4 frames
0000 000C ; Init loop counter to 12
0000 0100 ; All arrows cleared
0000 0000 ; Wait...
0008 ; ...8 frames
0000 01FF ; All arrows highlighted
0000 0000 ; Wait...
0008 ; ...8 frames
0000 00FF ; Loop back (blink all arrows 12 times)
0000 0201 ; A button is pressed
0000 0100 ; All arrows cleared
0010 F418 ; MESS_OUT write "MACHINE GUN"
0004 ; Wait 4 frames
0000 000C ; Init loop counter to 12
0000 0200 ; All buttons released
0000 0000 ; Wait...
0008 ; ...8 frames
0000 0201 ; A button is pressed
0000 0000 ; Wait...
0008 ; ...8 frames
0000 00FF ; Loop back (blink A button 12 times)
```
```

--------------------------------

### HOW_TO_PLAY Example Command List

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/HOW_TO_PLAY

An example command list used by the game NAM-1975. It demonstrates setting button and joystick states, updating text via MESS_OUT, and implementing blinking effects using loop counters and wait commands.

```assembly
0000 0200    All buttons released
0000 01FF    All arrows highlighted
0010 F3E2    MESS_OUT write "NAM 1975" "CONTROL HERO AND CURSOR"
0004         Wait 4 frames
0000 000C    Init loop counter to 12
0000 0100    All arrows cleared       <--------------,
0000 0000    Wait                                 |
0008         ...8 frames                             |
0000 01FF    All arrows highlighted                  |
0000 0000    Wait                                 |
0008         ...8 frames                             |
0000 00FF    Loop back (blink all arrows 12 times) --'
0000 0201    A button is pressed
0000 0100    All arrows cleared
0010 F418    MESS_OUT write "MACHINE GUN"
0004         Wait 4 frames
0000 000C    Init loop counter to 12
0000 0200    All buttons released     <--------------,
0000 0000    Wait...                                 |
0008         ...8 frames                             |
0000 0201    A button is pressed                     |
0000 0000    Wait...                                 |
0008         ...8 frames                             |
0000 00FF    Loop back (blink A button 12 times) ----'
```

--------------------------------

### Playing Sound Samples Example

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/Code

Example code to play back V ROM sound samples on CH1 with maximum volume.

```assembly
Example code to play back V ROM $000000-$00FFFF on CH1 with max volume. [[Category:Code]]
```

--------------------------------

### BIOS Message System Example

Source: https://wiki.neogeodev.org/index.php?action=edit&title=MESS_OUT

Example code demonstrating how to use BIOS message output commands to display text and control VRAM addresses. Requires setup of message buffers and pointers.

```Assembly
bset.b #0,BIOS_MESS_BUSY
movea.l BIOS_MESS_POINT,a0 ;Get current pointer in buffer
move.l #0,(a0)+ ;Direct commands
move.w #3,(a0)+
move.w #$7318,(a0)+
move.w #$0301,(a0)+
move.w #0,(a0)+
move.w #$100000,(a0)+
move.w #0,(a0)+
move.l #MESSAGE1,(a0)+
move.l a0,BIOS_MESS_POINT
bclr.b #0,BIOS_MESS_BUSY ;Ready to go
rts
```

```Assembly
MESSAGE1:
 dc.w $0001 ;Bytes, upper = $00, end code = $FF
 dc.w $00FF
 dc.w $2002 ;Auto-inc = $20
 dc.w $0003 ;VRAM address = $7024
 dc.w $7024
 dc.w $0004 ;Write "MESSAGE1"
 dc.l MS1
 dc.w $0005 ;Next line
 dc.w $0001
 dc.w $0006 ;Resume, write "MESSAGE2"
 dc.w $0005 ;Next line
 dc.w $0001
 dc.w $0007 ;Direct data output
 dc.b "MESSAGE3"
 dc.w $FF00 ;End code and pad byte
 dc.w $0005 ;Next line
 dc.w $0001
 dc.w $0108 ;8x16 write, fontset 1
 dc.b "ABCDE",$FF
 dc.w $0005 ;Next line
 dc.w $0001
 dc.w $0109 ;8x16 write, fontset 1
 dc.b 0,1,2,3,4,$FF
 dc.w $0005 ;Next 2 lines
 dc.w $0002
 dc.w $000A ;Sub list calls
 dc.l SUB_MESS
 dc.w $000A
 dc.l SUB_MESS
 dc.w $000A
 dc.l SUB_MESS
 dc.w $0000
```

```Assembly
MS1:
 dc.b "MESSAGE 1",$FF
 dc.b "MESSAGE 2",$FF
```

```Assembly
SUB_MESS:
 dc.w $090C ;Outputs $0022 9 times
 dc.w $0022
 dc.w $070D ;Outputs $0042 7 times with inc
 dc.w $0042
 dc.w $0005 ;Next line
 dc.w $0001
 dc.w $000B ;Return
```

--------------------------------

### Set Data Format - Byte Mode Examples

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/MESS_OUT

Examples demonstrating how to set the data format for byte-wise reading. These examples specify the upper byte for data and either an end code or a data length.

```Assembly
dc.w  $0001,$15FF  ;Data will be read in bytes, upper byte will always be $15, end code is $FF.
```

```Assembly
dc.w  $0101,$1520  ;Data will be read in bytes, upper byte will always be $15, data length is $20.
```

--------------------------------

### Set Data Format - Word Mode Examples

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/MESS_OUT

Examples showing how to configure the data format for word-wise reading. These commands set the data size or an end code when reading data in words.

```Assembly
dc.w  $0201,$8000  ;Data will be read in words, end code is $8000.
```

```Assembly
dc.w  $0301,$2044  ;Data will be read in words, data length is $2044.
```

--------------------------------

### NAM-1975 HOW_TO_PLAY Command List Example

Source: https://wiki.neogeodev.org/index.php?action=edit&title=HOW_TO_PLAY

A comprehensive example of a command list used by the game NAM-1975 for its 'how to play' screen. It includes initialization, button/arrow state changes, text displays, and loop structures.

```assembly
0000 0200 All buttons released
0000 01FF All arrows highlighted
0010 F3E2 MESS_OUT write "NAM 1975" "CONTROL HERO AND CURSOR"
0004 Wait 4 frames
0000 000C Init loop counter to 12
0000 0100 All arrows cleared <--------------,
0000 0000 Wait... | 0000 0000 Wait... |
0008 ...8 frames | 0008 ...8 frames |
0000 01FF All arrows highlighted | 0000 0201 A button is pressed |
0000 0000 Wait... | 0000 0000 Wait... |
0008 ...8 frames | 0008 ...8 frames |
0000 00FF Loop back (blink all arrows 12 times) --'
0000 0201 A button is pressed
0000 0100 All arrows cleared
0010 F418 MESS_OUT write "MACHINE GUN"
0004 Wait 4 frames
0000 000C Init loop counter to 12
0000 0200 All buttons released <--------------,
0000 0000 Wait... | 0000 0000 Wait... |
0008 ...8 frames | 0008 ...8 frames |
0000 0201 A button is pressed | 0000 0201 A button is pressed |
0000 0000 Wait... | 0000 0000 Wait... |
0008 ...8 frames | 0008 ...8 frames |
0000 00FF Loop back (blink A button 12 times) ----'
```

--------------------------------

### Example P bus values for sprites starting at X=0

Source: https://wiki.neogeodev.org/index.php/Rendering_logic

Provides example P bus values for five full-width sprites positioned consecutively starting at the X-coordinate 0.

```assembly
0000,0808,1010,1818,2020
```

--------------------------------

### Software DIPs Configuration Example (No Special Settings)

Source: https://wiki.neogeodev.org/index.php?action=edit&title=Software_DIPs

This example demonstrates the structure for defining game name, special settings list (none used), simple settings list, and their corresponding string descriptions and choices. Unused special settings are marked with $FFFF.

```assembly
dc.b "TEST ROM " ; Game name
dc.w $FFFF ; Special settings list (none used)
dc.w $FFFF
dc.b $FF,$FF
dc.b $24 ; Simple setting 1: 4 choices, default is #2
dc.b $02 ; Simple setting 2: 2 choices, default is #0
dc.b $00,$00,$00,$00,$00,$00,$00,$00 ; String table: dc.b "LIVES " ; Simple setting 1's description dc.b "1 " ; Simple setting 1's choices dc.b "2 " dc.b "3 " dc.b "4 " dc.b "HOW TO PLAY " ; Simple setting 2's description dc.b "WITH " ; Simple setting 2's choices dc.b "WITHOUT "
```

--------------------------------

### Example P bus values for sprites starting at X=1

Source: https://wiki.neogeodev.org/index.php/Rendering_logic

Illustrates P bus values for five full-width sprites placed adjacently starting at X=1. Note that NEO-ZMC2 may flip pixel pairs.

```assembly
0100,0908,1110,1918,2120
```

--------------------------------

### Calculate Bankswitching Address

Source: https://wiki.neogeodev.org/index.php?action=edit&title=NEO-PVC

Example calculation for determining the mapped data start address based on values written to the bankswitching registers.

```text
if $0131 is written to $2FFFF2, and $2A00 is written to $2FFFF0, the data mapped starts at $11312A.
```

--------------------------------

### CD Boot Process Initialization Steps

Source: https://wiki.neogeodev.org/index.php?action=edit&title=Boot_process

Outlines the initial steps for the CD boot process, including initializing RAM, loading the BIOS vector table, disabling interrupts, loading graphics data, and finally enabling interrupts.

```assembly
Init RAM
```

```assembly
Load BIOS vector table
```

```assembly
Disable interrupts
```

```assembly
Load DRAMs with graphics & stuff
```

```assembly
Enable interrupts
```

--------------------------------

### P bus values for sprite positioning

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/Rendering_logic

Examples of P bus values used to set sprite starting addresses for full-width sprites.

```text
0000,0808,1010,1818,2020
```

```text
0100,0908,1110,1918,2120
```

--------------------------------

### CD Drive Command 2: TOC COMMAND - GET TRACK MSF

Source: https://wiki.neogeodev.org/index.php?action=edit&title=CD_drive_commands

Retrieves the start MSF of a desired track. The upper digit of the frames' 4th bit indicates if it's a data track. Requires sub-command code 5.

```hex
20 00 00 05 ?? 00 00 00 00 ?
```

```hex
? 5 ???????? ? ?
```

--------------------------------

### Command 13: OPEN

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/CD_drive_commands

Opens the tray on the front-loading NeoGeo CD.

```APIDOC
## OPEN

### Description
Opens the tray on the front-loading NeoGeo CD.

### Request Body
- **Nibbles** (array) - Required - A sequence of 10 nibbles: [13, 0, 0, 0, 0, 0, 0, 0, 0, Checksum(D)]
```

--------------------------------

### Initialize Game Environment

Source: https://wiki.neogeodev.org/index.php?action=edit&title=Hello_world_tutorial

Sets up the stack pointer, kicks the watchdog, disables the pixel timer, clears interrupts, and enables system interrupts.

```assembly
Game:
  ; Label defined in the jump table
  lea $10F300,sp ; Init stack pointer
  move.b d0,REG_DIPSW ; Kick watchdog
  move.w #$0000,REG_LSPCMODE ; Make sur the pixel timer is disabled
  move.w #7,REG_IRQACK ; Clear all interrupts
  move.w #$2000,sr ; Enable interrupts
```

--------------------------------

### Example Tone Frequency Calculation

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/SSG

Example calculation for Note A4 (440Hz) to determine the required value.

```plaintext
Example: Note A4 (440Hz) would be 250000 / 440 =~ 568 = $238.
```

--------------------------------

### Command 0x3* and 0xa* Write Setup

Source: https://wiki.neogeodev.org/index.php/HD6301V1

Sets up a write operation for lower nibble values, checking for buffer selection.

```Assembly
F3B7: B6 00 E7   lda     $00E7		;a=$e7
F3BA: 81 FF      cmpa    #$FF		;==0xff?
F3BC: 27 18      beq     $F3D6		;yes? => branch $f3d6	//branch to error if $e7==0xff (no buffer selected)
F3BE: B6 00 E9   lda     $00E9		;a=$e9					//port3 data
F3C1: 84 0F      anda    #$0F		;a&=0x0f
F3C3: B7 00 F3   sta     $00F3		;$f3=a					//store lower nibble
F3C6: 71 EF F1   aim     #$EF,$F1	;$f1&=0xef				//clear bit#4
F3C9: B6 00 F1   lda     $00F1		;a=$f1
F3CC: 97 02      sta     $02		;port1=a				//update status port
F3CE: 86 FF      lda     #$FF		;a=0xff
F3D0: B7 00 F2   sta     $00F2		;$f2=a					//$f2=0xff
F3D3: 7E F1 93   jmp     $F193		;branch $f193
```

--------------------------------

### MGD2 ROM Filename Examples

Source: https://wiki.neogeodev.org/index.php?action=edit&title=MGD2

Examples of MGD2 ROM filenames demonstrating size, serial, and upload address encoding.

```text
N042001A.038
```

```text
N028015B.27C
```

--------------------------------

### Command 10: INIT

Source: https://wiki.neogeodev.org/index.php/CD_drive_commands

Initializes the CD drive, potentially seeking to the CD lead-in area.

```APIDOC
## INIT Command

### Description
Initializes the CD drive. This command may seek to the CD lead-in area.

### Method
N/A (Command-based)

### Endpoint
N/A (Command-based)

### Parameters
None specified

### Request Example
(Format not fully specified, but likely starts with command nibble)
```
Nibble  | 0 | ...
---|---|---
Value  | 10 | ...
```

### Response
None specified
```

--------------------------------

### Neo Turf Masters Example

Source: https://wiki.neogeodev.org/index.php/Timer_interrupt

An example illustrating the use of timer interrupts in Neo Turf Masters for graphical effects.

```APIDOC
## Example: Neo Turf Masters

### Description
This section provides a practical example of how timer interrupts are utilized in the game Neo Turf Masters to achieve specific graphical effects, such as perspective scrolling and line-based updates.

### Method
N/A (Usage Example)

### Endpoint
N/A (Usage Example)

### Scenario Breakdown:
- **A: Frame Start**
  - The timer is reloaded with a value of 41016.
  - The next interrupt is scheduled to trigger at point B, approximately 106 lines and 313 pixels into the frame.
  - This timing is used to set the scroll value for background elements like mountains.

- **B: Ground Area Start**
  - The timer is immediately reloaded to 767.
  - The timer mode is set to "reload when 0 is reached".
  - This configuration triggers interrupts every 2 lines, allowing for dynamic updates to the ground graphics to simulate a perspective effect.
  - A variable is used to track the number of ground lines rendered.

- **C: Ground Area End**
  - Once the required number of ground lines are rendered, the timer is immediately reloaded to 16383.
  - The timer mode is changed to "reload on first line of next frame".
  - The reload value is set to 41016, ensuring the next interrupt occurs later in the frame cycle.
```

--------------------------------

### Game Configuration with Time and Count Settings

Source: https://wiki.neogeodev.org/index.php/Software_DIPs

Example of a game configuration including time and count special settings, along with simple settings. Demonstrates default values for time (minutes/seconds) and count (0-100).

```assembly
    dc.b    "TEST ROM        "                 ; Game name
    dc.w    $4220                              ; Special setting 1: 42 minutes 20 seconds
    dc.w    $2042                              ; Special setting 2: 20 minutes 42 seconds
    dc.b    $42                                ; Special setting 3: 66
    dc.b    $64                                ; Special setting 4: 100 ("INFINITE")
    dc.b    $24                                ; Simple setting 1: 4 choices, default is #2
    dc.b    $02                                ; Simple setting 2: 2 choices, default is #0
    dc.b    $00,$00,$00,$00,$00,$00,$00,$00
    dc.b    "TIMER 1     "                     ; Special setting 1's description
    dc.b    "TIMER 2     "                     ; Special setting 2's description
    dc.b    "COUNTER     "                     ; Special setting 3's description
    dc.b    "COUNTER SPE "                     ; Special setting 4's description
    dc.b    "LIVES       "                     ; Simple setting 1's description
    dc.b    "1           "                     ; Simple setting 1's choices
    dc.b    "2           "
    dc.b    "3           "
    dc.b    "4           "
    dc.b    "HOW TO PLAY "                     ; Simple setting 2's description
    dc.b    "WITH        "                     ; Simple setting 2's choices
    dc.b    "WITHOUT     "
```

--------------------------------

### Real-time Fading Code Example

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/Graphics_Code

An example of code demonstrating real-time color fading by incrementing or decrementing target colors.

```Assembly
=Real-time fading code=
...
```

--------------------------------

### CONTROLLER_SETUP ($C004D4)

Source: https://wiki.neogeodev.org/index.php?action=edit&title=CONTROLLER_SETUP

The CONTROLLER_SETUP routine initializes controller configurations and updates the status bytes in BIOS RAM. It performs a series of checks to identify connected hardware.

```APIDOC
## CONTROLLER_SETUP ($C004D4)

### Description
Sets up controllers by detecting connected devices and updating the input status byte in BIOS RAM. Note that register contents are not preserved.

### Status Byte Values
- **0**: No connection (treated as standard controller)
- **1**: Standard controller
- **2**: Expanded controller (4P mode)
- **3**: Mahjong controller
- **4**: Keyboard

### MVS Logic
- If hard dip 3 is set, BIOS_P1STATUS is set to 3.
- Otherwise, status byte is set to 0 for all players.

### Neo Geo / Neo Geo CD Logic
- Performs 6 consecutive checks regardless of previous matches.
- Status bytes are only updated if the current value is 0 (1st check has highest priority).
- Detection involves writing configurations to controller outputs and checking specific buttons (D, C, Select, Start).
```

--------------------------------

### Initialize User RAM for Command 0

Source: https://wiki.neogeodev.org/index.php/USER_subroutine

Example of clearing backup RAM and initializing system variables during the Command 0 initialization phase.

```68k Assembly
	move.b	#$00,BIOS_USER_MODE
	lea	$100000,a0		;Start of game save block
	move	#$001F,d1		;32*4 longword writes = 512 bytes
	moveq	#0,d0
.cl:
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	dbf	d1,.cl
	move.b	d0,REG_WATCHDOG
...
        jmp     BIOSF_SYSTEM_RETURN
```

--------------------------------

### Example NGH Number in 68k Assembly

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/NGH

An example of how an NGH number might be represented in 68k assembly code, often as a word value.

```assembly
dc.w $1234 ;NGH
```

--------------------------------

### Art of Fighting 3 IPL.TXT example

Source: https://wiki.neogeodev.org/index.php/IPL_file

Example of an IPL.TXT file from Art of Fighting 3, including hex representations of character values.

```text
FIX_CD.FIX,0,00          46 49 58 5F 43 44 2E 46 49 58 2C 30 2C 30 30 0D 0A
PROG_CD.PRG,0,0          50 52 4F 47 5F 43 44 2E 50 52 47 2C 30 2C 30 0D 0A
PROG_CDX.PRG,0,058000    50 52 4F 47 5F 43 44 58 2E 50 52 47 2C 30 2C 30 35 38 30 30 30 0D 0A
FIX_DATA.PRG,0,0FD000    46 49 58 5F 44 41 54 41 2E 50 52 47 2C 30 2C 30 46 44 30 30 30 0D 0A
CNV_NM.PRG,0,0C0000      43 4E 56 5F 4E 4D 2E 50 52 47 2C 30 2C 30 43 30 30 30 30 0D 0A
HITMSG.PRG,0,170000      48 49 54 4D 53 47 2E 50 52 47 2C 30 2C 31 37 30 30 30 30 0D 0A
OBJACTLK.PRG,0,130000    4F 42 4A 41 43 54 4C 4B 2E 50 52 47 2C 30 2C 31 33 30 30 30 30 0D 0A
SSEL_CNV.PRG,0,15A000    53 53 45 4C 5F 43 4E 56 2E 50 52 47 2C 30 2C 31 35 41 30 30 30 0D 0A
SSEL_BAK.PRG,0,16F000    53 53 45 4C 5F 42 41 4B 2E 50 52 47 2C 30 2C 31 36 46 30 30 30 0D 0A
SSEL_SPR.PRG,0,19D000    53 53 45 4C 5F 53 50 52 2E 50 52 47 2C 30 2C 31 39 44 30 30 30 0D 0A
SND8V1CD.Z80,0,0         53 4E 44 38 56 31 43 44 2E 5A 38 30 2C 30 2C 30 0D 0A
JYOU.PCM,0,0             4A 59 4F 55 2E 50 43 4D 2C 30 2C 30 0D 0A
JYOU.PAT,0,0             4A 59 4F 55 2E 50 41 54 2C 30 2C 30 0D 0A
                       1A
```

--------------------------------

### Command 0xc* Buffer Copy and Write Setup

Source: https://wiki.neogeodev.org/index.php/HD6301V1

Copies storage buffer data and prepares for a subsequent 0x0d data write.

```Assembly
F426: B6 00 E7   lda     $00E7		;a=$e7
F429: 81 FF      cmpa    #$FF		;a==0xff?
F42B: 27 A9      beq     $F3D6		;yes? => branch f3d6	//error

F42D: B6 00 E9   lda     $00E9		;a=$e9					//port3 data
F430: 16         tab				;b=a
F431: 84 0C      anda    #$0C		;a&=0x0c				//keep bit#3 & bit#2
F433: 26 A1      bne     $F3D6		;!=0? => branch $f3d6	//error

F435: 71 EF F1   aim     #$EF,$F1	;$f1&=0xef				//clear bit#4
F438: B6 00 F1   lda     $00F1		;$a=f1
F43B: 97 02      sta     $02		;port1=a				//update status port

F43D: C4 03      andb    #$03		;b&=0x03				//keep bit#1 & bit#0
F43F: CE F4 FA   ldx     #$F4FA		;x=data table
F442: 3A         abx				;x+=b
F443: 3A         abx				;x+=b
F444: EE 00      ldx     (x+$00)	;x=(word)data[b]		//buffer addr
```

--------------------------------

### Command 0: Initialize User RAM and Peripherals

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/USER_subroutine

This snippet initializes the game's backup RAM with default data, sets up user RAM, display, and I/O. It's crucial to set BIOS_USER_MODE to 0 and kick the watchdog as interrupts are disabled during this process. The code clears a specified block of memory.

```68k Assembly
	move.b	#$00,BIOS_USER_MODE
	lea	$100000,a0		;Start of game save block
	move	#$001F,d1		;32*4 longword writes = 512 bytes
	moveq	#0,d0
.cl:
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	move.l	d0,(a0)+
	dbf	 d1,.cl
	move.b	d0,REG_WATCHDOG
...
        jmp     BIOSF_SYSTEM_RETURN
```

--------------------------------

### ADPCM-A Playback Example

Source: https://wiki.neogeodev.org/index.php/Special%3ASearch/Playing_sound_samples

Example code to play back ADPCM-A samples from V ROM. It sets volume, start/end addresses, and initiates playback on a specified channel.

```assembly
;playback parameters
CHMASK: equ $01
MVOL: equ $3F
CVOL: equ $C0+$1F
START: equ $0000
END: equ $00FF

PlayADPCMA:
	ld	de,PA_MVOL<<8 +MVOL		;master volume
	rst	$18
	ld	de,PA_CVOL<<8 +CVOL		;left/right/channel volume
	rst	$18
	ld	de,PA_STARTL<<8	+START AND $FF	;start address low
	rst	$18
	ld	de,PA_STARTH<<8	+START / $100	;start address high
	rst	$18
	ld	de,PA_ENDL<<8	+END AND $FF		;end address low
	rst	$18
	ld	de,PA_ENDH<<8	+END / $100		;end address high
	rst	$18
	ld	de,PA_CTRL<<8	+CHMASK		;play this channel
	rst	$18	
	ret

```
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