Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!sdcsvax!ucbvax!AI.AI.MIT.EDU!MAP From: MAP@AI.AI.MIT.EDU.UUCP Newsgroups: comp.dcom.modems Subject: Standards are wonderful, everyone should have their own (re: RS232) Message-ID: <249025.870901.MAP@AI.AI.MIT.EDU> Date: Tue, 1-Sep-87 14:46:20 EDT Article-I.D.: AI.249025.870901.MAP Posted: Tue Sep 1 14:46:20 1987 Date-Received: Thu, 3-Sep-87 01:01:31 EDT References: Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 22 James Starr writes: The RS-232C standard is undoubtedly the most corrupted and bastardized standard in the world. In fact the only thing I have not seen changed is the physical size of the connector, the pin spacing and pin 7 being signal ground. I have even seen these changed!!! The RS232 standard is a marvel of ambiguity. The only thing it clearly seems to state is what the voltage levels are (for high and low, it is occasionally unclear as to which is True/False or 0/1). It seems to be sufficiently carefully worded that anybody who reads it gets a clear unambiguous meaning, however not everyone gets the same one. In over 10 years of working with ``RS232 compatible'' devices, I have found that immediate inter-operability between different vendors was the exception rather than the rule. This is partially supported by the growing market in companies supplying interconnection, usually cables with funny wire swaps, but even fancy boxes to translate RTS/CTS to XON/XOFF and similar things. I have always read the phrase ``RS232 compatible'' as meaning an experienced RS232 hacker can probably get simple functionality in less than 1 whole day. Complete functionality is, of course, a different matter and has been known to require weeks or even months of tweaking to get it right.