[net.dcom] RS-232 from the horse's mouth.

lmc@denelcor.UUCP (Lyle McElhaney) (11/01/83)

My copy of the RS-232C standard (dated August of 69) says:

    "3.1
        The interface between the data terminal equipment and the data
        communication equipment is located at a pluggable signal interface
        point between the two equipments.  The female connector shall be
        associated with, but not necessarily physically attached to the
        data communication equipment and should be mounted in a fixed
        position near the data terminal equipment....  An extension cable
        with a male connector shall be provided with the data terminal
        equipment. ....

    3.1.1
        When additional functions are provided in a separate unit inserted
        between the data terminal equipmentand the data communication
        equipment, the female connector, as indicated above shall be
        associated with the side of this unit which interfaces with the
        data terminal equipment while the extension cable with the male
        connector shall be provided on the side which interfaces with the
        data communications equipment."

The pin assignments for 25 pins are described (of course), but the physical
description of the connector is not given. Appendix I states:

        "While no industry standard exists which defines a suitable
        interface connector, it should be noted that commercial products
        are available which will perform satisfactorily as electrical
        connectors for interfaces specified in RS-232C, such as those
        connectors meeting Mil Spec MIL-C-24308 (MS-18275) or equivalent.

        It is not intended that the above reference be considered as part
        of RS-232C or as a standard for the devices to which reference is
        made."

As Lazarus Long says:

        "What are the facts?  Again and again and again - what are the
        facts?  Shun wishful thinking, ignore devine revalation, forget
        what the stars fortell, avoid opinion, care not what the neighbors
        think, nevermind the unguessable "verdict of history" - what are
        the facts, and to how many decimal places?  You pilot always into
        an unknowable future; facts are your single clue.  Get the facts!"

	:-)
				Lyle McElhaney
				...(hao,nbires,brl-bmd)!denelcor!lmc