The Apple Newton Fax Modem for use with Apple's line of Newton MessagePads and eMate 300 came in both an external and internal PCMCIA versions. The external version seen here is a small box, powered by two AA batteries or by a standard Newton power adapter and interfaces with the MessagePad via a short serial cable. Both modems operate at a maximum of 2400 bits per second for data and 9600 for fax transmission.
The modem has no controls of any kind with a low battery LED being the only indicator. As it has no power switch the modem turns off automatically with no activity on the serial port. The only connectors on the modem include a single rj-11 telephone jack and the short mini DIN-8 serial cable mentioned earlier.
Although I have never tried, I assume the modem will work on a Macintosh computer aswell.