Modem Cartridge

Modem Library ROM

The ROM is 4MB, it contains a header, as well as three different kinds of ELF library files:

    0x40 - Debug
0x100000 - CPU
0x200000 - RSP

The ROM is mapped at 0x18000000.

Modem Registers

0x0FFD0000 - For DMAs? Signal?
0x0FFD00C0 - Main Register Control/Status
  bit16 - Signal? (Used in asicInterruptHandler)
          Might send CART interrupts all the time, it also reads.
  bit17 - IM
  bit18 - ? (Used in asicInterruptHandler)
  bit19-21 - IF
  bit22 - RE (Seize Relay, connect?)
  bit23 - ? (Used in asicInterruptHandler)
  bit24 - RI (Ring Indicator?)
  bit26 - PD (Pulse Dial?)
  bit27 - RS (Reset)
          Resets the register to 0x00000000