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From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.amiga,comp.sys.atari.st,comp.sys.cbm
Subject: Re: Amiga and MIDI
Message-ID: <876@neoucom.UUCP>
Date: 22 Dec 87 16:31:17 GMT
References: <2568@gryphon.CTS.COM> <2618@cbdkc1.ATT.COM> <2267@tekig4.TEK.COM> <467@gethen.UUCP>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 62
Summary: RS-232 "standard"


Yes, you can order pulication RS-232-C form Electronic Industries
Association, 2001 Eye Street, Wash DC 20006.  It is about 24 pages.
Back when I got mine about 10 years ago, it cost $5.10.

While going into excursiating detail about the elctrical
characteristics of the singals, it makes omits two useful items.
First the temporal relationships of control signals.  (It does say
which ones should be on/off simultaineously for certain
conditions.)  Actually, RS-334 defines the temporal reationships.
Second, RS-232-C says nothing about the physical design of
the connector beyond recommending that it have 25 pins.  

Section Three says:
   3.1   The interface between the data terminal equipment and data
   communications equipment is located at a pluggable connector
   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.  The use of an extension cable on the data
   communication equipment is permitted. An extension cable with a
   male connector shall be provided with the data terminal
   equipment [Ha! --Bill].  The use of short cables (each less than
   approximately 50 feet or 15 meters) is recommended; however,
   longer cables are permissible, provided that the resulting load
   capacitance (CL of fig. 2.1), measured at the interface point
   and including the signal terminator, does not exceed 2500
   picofarads.

   3.1.1  When additional functions are provided in a separate unit
   inserted between the data terminal equipment and the data
   communication equipment (See section 1.7), 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 communication equipment.

That's it.  But Appendix I suggests:

                     Interface Connector

   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 electrial
   connectors for interfaces specified in RS-232C, such as those
   connectors meeting Military Specification MIL-C-24308 (MS-18275)
   or quivalent.

   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.


Holy avoiding the issue, Batman.


Ahhh, the beauty and simplicity of Midi cables.  One pin
arrangement, one set of allowable pins, one baud rate.

Enjoy the Holidays,
--Bill