NEO-FTC1B board

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Picture courtesy of [MVS-Scans]. EDGE1 is on the right, EDGE2 on the left.

Multiplayer extension board used with Kizuna Encounter - Super Tag Battle to allow 4 players to play on the same system. It forms a Y splitter with 2 JAMMA edges to connect two displays, two pair of speakers and two sets of 2-player controls.

It multiplexes the inputs by using selection signals coming from a 4-wire (actually 2 used) cable that connects to the output port of the MV1B or MV1C, it also provides video signal buffering and power for the speakers (power amp under the heatsink).

Inputs

The REG_POUTPUT register is used to detect the board and select which set of inputs to read.

  • OUT1: set selection
  • OUT2: seems unused
  • OUT3: used for board detection by the system ROM
OUT1 P1 reads P2 reads
low EDGE 1 P1 EDGE 2 P1
high EDGE 1 P2 EDGE 2 P2

When OUT3 is high, it simulates presses on particular buttons:

  • EDGE 1 player 1 button A
  • EDGE 2 player 1 button A
  • EDGE 1 player 2 button B
  • EDGE 2 player 2 button B

Schematic

Ftc1b schematic.png