NEO-CMC



Late SNK custom chip used for protection, bankswitching and latching on CHAFIO CHA boards.

Descrambling/decryption infos can be found in [MAME:prot_cmc.c]

Versions
This chip is a TC190G series Toshiba ASIC developed between 1990 and 1994.

The datasheet apparently can't be found anymore for any of the known types: (probably others...)
 * TC190G06CF7008
 * TC190G06CF7042
 * TC190G06CF7050

SNK merged the following designs into this chip:
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time (NEOCMC42).
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data and Sound Driver ROM data in real time (NEOCMC50).
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time (NEOCMC42).
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data and Sound Driver ROM data in real time (NEOCMC50).
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time (NEOCMC42).
 * New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data and Sound Driver ROM data in real time (NEOCMC50).

The first released NEO-MVS CHAFIO PCBs came out with the 042 version of NEO-CMC, on the following cartridges:
 * Zupapa!
 * The King of Fighters '99 - Millennium Battle
 * Ganryu
 * Garou - Mark of the Wolves
 * Strikers 1945 Plus
 * Prehistoric Isle 2
 * Metal Slug 3
 * Bang Bead
 * Nightmare in the Dark
 * Sengoku 3

On this version only the S1 and C ROMs are encrypted and M1 remains unencrypted. Almost one year later, SNK decided to add one more layer, this time also encrypting M1. This new NEO-CMC chip had the 050 reference and was found in the following cartridges:
 * Jockey Grand Prix
 * The King of Fighters 2000
 * The King of Fighters 2001
 * Metal Slug 4
 * Rage of the Dragons
 * The King of Fighters 2002
 * Matrimelee
 * Pochi and Nyaa
 * Metal Slug 5
 * SNK vs. Capcom - SVC Chaos
 * Samurai Shodown V
 * The King of Fighters 2003
 * Samurai Shodown V Special

Until today, nobody has released a cloned chip on the underground market.

Fix handling
See fix bankswitching.

Encryption
Todo.

=Pinout=

OpenOffice Draw file:

Signals: CXe_D[0..15]: C odd data bus CXo_D[0..15]: C even data bus CX_A[0..21]: C1~8 address bus Pin : 32 connects to Mitsumi (PST600D) reset generator to re-initialize the NEO-CMC in case of power failure. Pins: 87 and 88 contains a RC circuit clock driver like in a 8085 with X1 and X2 pinouts Pins: 89 and 92 are interconnected. Pin : 94 is configured in: NEO-MVS CHAFIO as NC      NEO-AEG CHAFIO as 12M Pin :147 is configured in: NEO-MVS CHAFIO (2003.07.24) as M1_CE NEO-MVS CHAFIO (1999.06.14) as NC     NEO-AEG CHAFIO (2003.07.24) as M1_CE NEO-AEG CHAFIO (1999.08.10) as NC

Comparing MVS and AES Cartridges vs MVH PCBs: Pin :147 is configured in: NEO-MVH MVOC  (2003.11.03) as M1_CE (KOF2003 pcb) NEO-MVH MVOBR (2003.08.04) as M1_CE (MSLUG5 pcb) NEO-MVS CHAFIO (2003.07.24) as M1_CE NEO-AEG CHAFIO (2003.07.24) as M1_CE NEO-MVS MVOB  (2003.07.09) as NC    (SVC pcb - fixed by wirewrap) NEO-MVS MVO   (2003.06.05) as NC    (SVC pcb) NEO-MVS CHAFIO (1999.06.14) as NC NEO-AEG CHAFIO (1999.08.10) as NC Pin : 152 is configured in: NEO-MVH (MVOC) as VCC NEO-MVH (MVO, MVOB, MVOBR) as GND NEO-MVS (ALL) as GND NEO-AEG (ALL) as GND

Final Notes NOTE1: There are no pinout differences between NEO-CMC42 and NEO-CMC50 however, differences can be spotted between previous and later board releases with respect to some setup lines and pin 147. A substantial setup difference can be found comparing the boards of AES and MVS releases. The way the chip access and delivery the graphic data is different between them and both configurations are available inside the NEO-CMC that is configured by the setup of the board itself. So the NEO-CMC is interchangeable between boards between MVS, AES, and MVH embedded. See the releases at (CHAFIO) NOTE2: In case somebody wonders, it's impossible to downgrade or upgrade NEO-CMCs between different versions (from 42 to 50 and vice-versa). The reason is that it's impossible without preparing the game for that and the algorithm to do it is unknown.