public void handler(int offset, int data) {
            switch (offset) {
                case 0x000:
                    break;

                case 0x400: /* most games */

                case 0x500: /* tdfever */

                    snk_soundlatch_w(0, data);
                    break;

                case 0x700:
                    if ((cpuA_latch & SNK_NMI_PENDING) != 0) {
                        cpu_cause_interrupt(0, Z80_NMI_INT);
                        cpuA_latch = 0;
                    } else {
                        cpuA_latch |= SNK_NMI_ENABLE;
                    }
                    break;

                default:
                    io_ram.write(offset, data);
                    break;
            }
        }