jd@sun.UUCP (jean daniel nicoud) (08/09/83)
A new serial transfer line standard The IEEE Microprocessor Standard Committee has started a new project, code-named P-1011, for a simple serial transfer transfer line, also referred as A5 (Asynchronous 5 volts). It is intended to replace the RS-232 except for expensive modems. Draft D1.1 proposes three implementations: A5/T is primarily intended for keyboards and mice. A 4-pin telephone jack provides power and bidirectionnal transfers on TTL-like signals. A5/D uses the RS-422 electrical specs (balanced pairs) and a sub-D9 connector. This allows long distances and high speed, and is compatible with the most stringent FCC rules. The door is still open for A5/F, upward compatible (small adapter required). A5/F may use special ICs, but A5/T and A5/D are compatible with all the programmable interface and one-chip microcomputers having a serial I/O port. Compared with RS-232, A5 does not need +12V and -12V, is symmetrical (no DTE/DCE relationship), and defines standard software protocols for handling peripherals. A5 is primarily designed for human-controlled peripherals in a personal computer environnment. If A5 was used on all systems, one could for instance travel with one's own keyboard and mouse, and stay efficient and happy on all systems, would they be a terminal, a low-cost personal computer or a professionnal workstation. For more information and participation to the working groups, write to one of the chairmen: J.D. Nicoud, LAMI-EPFL, 16 Bellerive, CH-1007 Lausanne, Telex 26420 Matt Biewer, ProLog Corp, 2411 Garden Rd, Monterey, CA 93940, Tel (408) 372-4593 Before August 18, you can reach JD Nicoud at sun!jd@BERKELEY