[time-nuts] Z3805 utility, Was: AW: (no subject)

Bob Camp lists at rtty.us
Sun May 23 13:52:04 UTC 2010


Hi

The DB-25 connector, with the pinouts detailed in the "C" rev and the levels in "C" all existed in the early 60's / late 50's. It took them until "C" to get a spec that was at least close to describing what was already common practice, the A and B revs both had a lot missing in them.

Bob

On May 23, 2010, at 9:05 AM, Mike S wrote:

> At 08:27 AM 5/23/2010, Bob Camp wrote...
>> As mentioned in the wiki, the "standard" dates to 1969. The interface dates to (at least) 1962.
> 
> No, it says RS-232-C dates to 1969. The C revision was at least the 3rd (probably the 4th, as they likely did not start with RS-232-A). It is very probable that an earlier revision existed in 1962.
> 
> I have no proof, but once read that the earlier revisions did not fully specify the connector, only that it have 25 pins, and that the Cannon DB-25 just became the convention and only later was put in the standard. 
> 
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