[conspire] DE-9, not DB-9 (was: conspire list hacked?)

[Texx]

The computer industry found itself in a spot with multiple interfaces for
multiple things.
MoBos were MUCH easier to build if you could cut down on the number of
different types of interfaces.
The original mouse port was a db9 serial.

The original serial interface was designed for terminals and modems.
The RS-232 standard actually has TWO data channels in it, the second being
a much slower interface.
This secong channel was designed for controling the modem and the dialer.
The "ATDT" command set allowed "in band signalling" and this removed the
need for the second data channel.
The "Xon-Xoff" protocol removed the need for hardware handshaking.
The DB25 which was about 3in wide shrunk to the DB-9 that was only 3/4in
wide.

What we got from USB, was the ability to use the same protocol for
keyboard, mouse, serial, external drives, and in some cases audio & video.

USB serial ?  How does that differ from RS-232?
USB serial is "TTL level" which means the signal is either 0 or +5 and
thats it.
RS232 is interesting.  It was designed to tolerate long cable lengths.
Ones were between -5 and -25, zeros were between +5 & +25.  Voltages
between -5 & +5 were invalid as weere voltages in excess of 25 or either +
or -.
Default USB serial is 115k baud.

By moving to USB, you could also plug any usb device into any usb socket as
the bus queries the device and figures out whats what.
Its all about making computers easier to use so that even morons could use
one.

Technology has marched so far along that even the dimwitted YOTUS
(Twitterer Of The USA) is able to use one!





On Mon, Feb 18, 2019 at 11:21 AM Michael Paoli <
Michael.Paoli at cal.berkeley.edu> wrote:

> DE-9 (or DE-09), *NOT* DB-9 (nor DB9 nor DB-09).  Many folks get this
> wrong ... sometimes even vendors' documentation is incorrect.
> A DB-9 (were there such an animal) would have the same shell size as
> a DB-25, but with only 9 pins.
> Once upon a time, Electronics, Etc. in Berkeley had an excellent
> display of the various connectors ... and their proper labeling.
>
> See also: https://en.wikipedia.org/wiki/D-subminiature
>
> > From: "paulz at ieee.org" <paulz at ieee.org>
> > Subject: Re: [conspire] conspire list hacked?
> > Date: Mon, 18 Feb 2019 18:32:00 +0000 (UTC)
>
> > Regarding USB cables.  Before USB there were serial ports.  In those
> > days, we all had a variety of devices with the DB-9 connector.
> > Using a new connector with an older device was a challenge.  Several
> > companies offered adapter cables.  The ones by FTDI actually worked
> > well.  On the outside they looked like a simple cable with USB A
> > connector on one end and DB9 on the other.  Molded into the cable
> > was a custom chip that provided an active interface.  More than
> > once, I had to explain to someone that they couldn't just use an
> > Ohmmeter to figure out the pin connections.
>
>
> _______________________________________________
> conspire mailing list
> conspire at linuxmafia.com
> http://linuxmafia.com/mailman/listinfo/conspire
>


-- 

R "Texx" Woodworth
Sysadmin, E-Postmaster, IT Molewhacker
"Face down, 9 edge 1st, roadkill on the information superdata highway..."
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