NEO-CMC

"CMC42" chip on a MVS cartridge. Picture courtesy of [MVS-Scans].

The most "basic" information can be found at [MAME:neocrypt.c]

The detailed information can be checked "only here": The NEO-CMC Chip is a Asic (Application Specific Integrated Circuit) device. This device can be programmed only once after severals protptyped been developed in a basic FPGA (Field Programmable Gate Array).

The Toshiba as partner to SNK, not only made solution to hold data on it's Mask Roms (TC5xxxx) as used its abstraction Solutions to help SNK try to avoid the Piracy. Toshiba until 1995 had a line of Asics called TC190G series, the evolution can be found here [Toshiba Technology RoadMap].

The series TC190G cannot be found in datasheets anymore, but in past days it had some models for this line:

• TC190G06CF7008
• TC190G06CF7042
• TC190G06CF7050

Apparently the models last two models was used because the number of internal memory needed inside these chips to accommodate the following logics:

• NEO-ZMC
• NEO-273
• And a new scrambling system for that interlaces M1+CX+S1 ROM data

Than, released model of CMC was NEO-CMC42 in the following cartridges: ID - TITLE NAME 070 - Zupapa 251 - King Of Fighters 99 252 - Ganryu 253 - Garou Mark Of the Wolves 254 - Strikers 1945 255 - Prehistoric Isle 2 256 - Metal Slug 3 259 - Bang Bead 260 - Nightmare in the Dark 261 - Sengoku 3

This version had only S1 and CRoms Encrypted and M1 was in normal condiction (unencrypted)

This was just a just a test to see if SNK and Toshiba could be more further in protection

Next SNK just incremented a new scramble and some tests point into M1 to validate the sync decryption and this caused to SNK release the model NEO-CMC50 on the following cartridges: ID - TITLE NAME 008 - Jockey Grand Prix 257 - King Of Figthers 2000 262 - King Of Figthers 2001 263 - Metal Slug 4 264 - Rage of the Dragons 265 - King Of Fighters 2002 266 - Power Instinct - Matrimele 267 - Pochi to Nyaa 268 - Metal Slug 5 269 - SNK vs Capcom Chaos 270 - Samurai Showdown Zero / Samurai Showdown 5 271 - King of Fighters 2003 272 - Samurai Showdown Zero Special / Samurai Showdown 5 Special

About JockeyGP some peoples talk to not be a official release but it´s not true. Because they had used the REAL Encryption that cannot be mocked in NEOCMC50. Only the Toshiba and SNK knewed the encryption and never one Copy card has published any algorithm until today that can mock NEOCMC50. Explanation Later.

File:Brd cmcnoref.jpg

"CMC50"

Also found on ROM-only arcade boards, without the "NEO-CMC" marking.

Pinout

Notes:

• C_e_D[0-15]: C1/C3/C5/C7 data bus
• C_o_D[0-15]: C2/C4/C6/C8 data bus
• CX A[0-21]: C1/C2/C3/C4/C5/C6/C7/C8 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 short circuited in Cartridge board.