NEO-CMC: Difference between revisions
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[[File:brd_cmcnoref.jpg|thumb|"CMC50"]] | [[File:brd_cmcnoref.jpg|thumb|"CMC50"]] | ||
Late SNK | Late SNK custom chip used for protection, bankswitching and latching on [[CHAFIO]] [[CHA board]]s. | ||
Descrambling/decryption infos can be found in [[https://github.com/mamedev/mame/src/devices/bus/neogeo/prot_cmc.cpp MAME:prot_cmc.c]] | |||
==Versions== | ==Versions== | ||
This chip is a TC190G series Toshiba ASIC developed between 1990 and 1994 | 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: | The datasheet apparently can't be found anymore for any of the known types: | ||
| Line 17: | Line 16: | ||
SNK merged the following designs into this chip: | SNK merged the following designs into this chip: | ||
*NEO-ZMC | *{{Chipname|NEO-ZMC}} | ||
*NEO-273 | *{{Chipname|NEO-273}} | ||
*New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time. | *New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time. | ||
Revision as of 04:37, 16 August 2016
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
- 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.