System ROM

(Enlarge) Configuration and book keeping menus in the SP-2 MVS BIOS

The system ROM (often called BIOS) is a ROM containing code for the 68k startup program, lookup tables, and various generic functions which can or must be used by games. They are present in all hardware types in various versions. The NeoGeo CD system ROM also contains graphics, sound, and Z80 code.

The official system ROMs have their nationality set by the byte at address $000401 (0=Japan, 1=US, 2=Euro).

The type is set by the byte at $000400 (0=AES, $80=MVS).

Hashes

Copied from MAME's source code.

Version	CRC32	SHA-1
SP-S	c7f2fa45	09576ff20b4d6b365e78e6a5698ea450262697cd
SP-S2	9036d879	4f5ed7105b7128794654ce82b51723e16e389543
SP-U2	e72943de	5c6bba07d2ec8ac95776aa3511109f5e1e2e92eb
SP-E	2723a5b5	5dbff7531cf04886cde3ef022fb5ca687573dcb8
SP-US-V2	62f021f4	62d372269e1b3161c64ae21123655a0a22ffd1bb
ASIA-S3	91b64be3	720a3e20d26818632aedf2c2fd16c54f213543e1
SP-J3	f0e8f27d	ecf01eda815909f1facec62abf3594eaa8d11075
SP-J2	acede59c	b6f97acd282fd7e94d9426078a90f059b5e9dd91
SP-J1	9fb0abe4	18a987ce2229df79a8cf6a84f968f0e42ce4e59d
SP-45	03cc9f6a	cdf1f49e3ff2bac528c21ed28449cf35b7957dc1
SP-J3	dff6d41f	e92910e20092577a4523a6b39d578a71d4de7085
SP-1V1	162f0ebe	fe1c6dd3dfcf97d960065b1bb46c1e11cb7bf271
NEO-EP0	d27a71f1	1b3b22092f30c4d1b2c15f04d1670eb1e9fbea07

Contents

Lookup tables

See system ROM tables.

AES

Size: 128KiB. Called NEO-EP0.

MVS

Toshiba SP-S2 on a 1FZS MVS slot.

Size: 128KiB. Called SP-S2, "SP-E"... Different names according to nationality.

Graphic visualisation of sp-s2.bin:

binviewsp2.png

CD/CDZ

File:Cd2 bios.jpg

TOP-SP1 BIOS ROM on a CDM3-2 board.

File:Brd spj.jpg

SPJ Japanese BIOS on a ROM-only arcade board. Picture courtesy of [MVS-Scans].

Size: 512KiB.

• FRONT-SP1 (Front loader)
• TOP-SP1 (Top loader, LC8953)
• TOP-SP2 (Top loader, LC98000)
• TOP-SPD (CDZ)

Contains Z80 and 68k programs, PCM sound, and graphics which are copied to the corresponding DRAMs at boot time. There is no SFIX or SM1 ROMs in CD systems (but still a LO ROM).

The CD1 and CD2 system ROMs (FRONT-SP1 and TOP-SP1/SP2) include the "Ver 3.0 by Mr.Noric.1993/11/10 14:00" Z80 sound driver.

The CDZ version includes the "Ver 3.0 by MAKOTO.04/03/10 to SK" driver.

The CD1 and CD2 system ROMs contain credits, organized to be displayed on the fix layer (how can this be seen on screen ?):

CREDITS
SOFTWARE NORIYUKI HIGASHI
HARDWARE MOTOO YOKOYAMA TOSHIYA YAHARA
GRAPHICS OTIAI
SPECIAL  JON   GUSO
THANKS   CURRY SHIMIZU
SNK ALL STAFF

Noriyuki Higashi is the infamous "Mr.Noric".

Toshiya Yahara is cited as the inventor of the NeoGeo Pocket power supply in an SNK patent.

Graphic visualisation of a CDZ BIOS dump, with separated data blocks:
File:Cdzbiosgfx.png

UniBIOS

Hacked MVS system ROM with various added functionalities such as cheats, CRC calculation, jukebox, error handling. See Universe BIOS.

Neopen BIOS

Opensource AES/MVS system ROM in development. See Neopen BIOS.