FaxModem/V.42bis  (250-3028)     Cable Requirements    Faxback Doc. # 3289

Special Cable Requirements for FaxModems with V.42bis/MNP5

To work with V.42bis and MNP5, you also need a cable that supports
hardware flow control.  For a PC compatible, the RTS and CTS lines MUST be
connected.  Making sure the cable has AT LEAST 9 wires connected is a good
indicator that they are.  For the Mac, the cable MUST follow the exact
connection scheme shown in Appendix F: Mac V.42/Fax Cable Connections of 
your owners manual.

Synchronous Communications

The modem is capable of communicating asynchronously with a computer while
communicating synchronously with another modem.  This speeds up data flow
by eliminating "start" and "stop" bits used in asynchronous communication.

To do ANY type of synchronous communication, you must have a special
synchronous port.  The most common application of synchronous operation
will be with mainframe computers or minicomputers, since they normally are
equipped with a synchronous port.  For synchronous communication between
the computer and modem, special software will be required.  If this
software is not included, check with the computer or synchronous card 
vendor for their recommendation.

(br/all-11/3/94)