NEO-CMC

Package	QFP180
Manufacturer
First use	1999 ?
Used on	CHAFIO...

File:Brd cmcnoref.jpg

"CMC50"

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:

• TC190G06CF7008
• TC190G06CF7042
• TC190G06CF7050

(probably others...)

SNK merged the following designs into this chip:

• NEO-ZMC
• NEO-273
• PRO-CT0
• New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time.

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: File:Neocmc 7050 7042.odg

Signals:

• C_e_D[0..15]: C odd data bus
• C_o_D[0..15]: C even data bus
• CX A[0..21]: C1~8 address bus
• Pins 87,88 contains a RC circuit clock driver like in a 8085 with X1 and X2 pinouts
• Pins 89 and 92 are shorted.