The Link1 TADILB modem operates at 600 and 1200 bps, synchronous or asynchronous, with V.23 modulation. The modem accepts external transmit clock on pin 24. The modem operates in Link1 DFSK mode (differential frequency shift key) at 600 and 1200 bps. Full 13.5" PC card, 7.25" half card size, and standalone configurations are available. The pc card uses the internal pc ISA bus only for power from the pc bus.