Board only used for Metal Slug X - Super Vehicle-001. One of the few MVS PROG boards using the SLOTCS pin.
J1~J4: PLD P2 ROM configuration ?
- 4x 4MiB mixed ADPCM ROMs.
- 1 MiB + 2x 4MiB P ROM ?
An Altera MAX EPM7128 chip is included for:
- Protection read/write accesses ($2FFFE0+)
- Bankswitching ($2FFFF0+ as with PROGBK1 games)
- Controlling /E and /G pins on both P1 and P2
- P1 + P2 D0-D7 pass through (P ROMs don't connect straight to D0-D7 on the cart edge)
- Decoding V ROM output enables from PCM address inputs
The chip seems to die frequently. Since it also does some other essential things, either the ROMs have to be transplanted to a PROGBK1 or the dead PROGEOP has to be modified. A hacked P1 ROM needs to be used. The MAX chip combines what was done with the LS08, LS74 and LS139 on regular BK1 boards so those circuits have to be added manually to revive the game without the MAX.
- Connected to the PLD through a 245 chip. Apart from that it's completely isolated from everything else ?
- Maybe it does the protection. PLD forwards read/write requests through 245 from $2FFFE0+ ?
MAME currently patches out the protection code instead of emulating it: (mslugx_install_protection)