Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting)

From	William Unruh <unruh@invalid.ca>
Newsgroups	comp.os.linux.misc
Subject	Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting)
Date	2016-03-18 15:33 +0000
Organization	A noiseless patient Spider
Message-ID	<nch74q$13s$1@dont-email.me> (permalink)
References	(5 earlier) <f23rrcxb3b.ln2@goaway.wombat.san-francisco.ca.us> <ncempu$hfh$1@dont-email.me> <ncenoq$mgt$1@dont-email.me> <c4crrc-agg.ln1@Telcontar.valinor> <ncgr7t$uft$1@news.albasani.net>

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On 2016-03-18, The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 17/03/16 19:11, Carlos E.R. wrote:
>> On 2016-03-17 18:02, Bobbie Sellers wrote:
>>
>>>      The engineers who designed and built them wrote the cautions
>>> into the manuals and expected(foolishly) that people who valued their
>>> hardware would read the manuals and so forth. By the time I got to
>>> my Commodore Amigas I had learned that lesson well.  I was
>>> happy when USB came along and it was no longer the necessity it
>>> formerly was.
>>
>> The RS232 serial port, which is a very old design, was prepared from the
>> start for "hot plug". If I recall correctly, it also accepts a range of
>> voltages, whereas USB doesn't.
>>
> Yet I saw an RS232 destroyed by hot plugging..
>
> WE worked it out, finally. The laptop on which the RS232 port resided, 
> had a mains filter. The connected capacitors between mains live and the 
> metal frame of the laptop and between neutral and the metal frame of the 
> laptop.
>
> Unfortunately the laptop came with a two wire lead to the mains, with no 
> earth, so the frame (and all the electronics inside)  sat at 110VAC via 
> the capacitors.

Yes, it is really hard to fight against really really gross engineering
incompetence. They were lucky it was just an rs232 port that got fried,
and not the users. 

>
> Subsequent tests showed a small spark when the laptop was connected to 
> anything earthed, and of course if any pin other than earth to earth 
> made contact first, that was the pin that got the 110V.
>
> However none of that is relevant to plugging in a passive device and 
> back in the day I have hotplugged loads of keyboards at least with no 
> issues, on PS2 connectors.
>
> We used to run headless servers and that was one way if we couldn't 
> reach them via the network, that we would see what was up - screen and 
> keyboard.
>
> WE didn't use mice however. strictly 80x25
>
>

Thread

Cursor while booting Helge <w4hw4h.hh@gmail.com> - 2016-03-12 02:54 -0800
  Re: Cursor while booting Andreas Kohlbach <march.10.ankman@spamgourmet.net> - 2016-03-12 15:08 -0500
  Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-13 00:26 -0800
    Re: Cursor while booting William Unruh <unruh@invalid.ca> - 2016-03-13 16:26 +0000
    Re: Cursor while booting Andreas Kohlbach <march.10.ankman@spamgourmet.net> - 2016-03-13 17:05 -0400
      Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-15 02:48 -0700
        Re: Cursor while booting Robert Heller <heller@deepsoft.com> - 2016-03-15 06:25 -0500
          Re: Cursor while booting gazelle@shell.xmission.com (Kenny McCormack) - 2016-03-15 13:32 +0000
            Re: Cursor while booting Reinhardt Behm <rbehm@hushmail.com> - 2016-03-15 22:12 +0800
            Re: Cursor while booting Robert Heller <heller@deepsoft.com> - 2016-03-15 10:48 -0500
              Re: Cursor while booting gazelle@shell.xmission.com (Kenny McCormack) - 2016-03-16 09:20 +0000
              Re: Cursor while booting Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-03-16 20:15 +0100
                Re: Cursor while booting Keith Keller <kkeller-usenet@wombat.san-francisco.ca.us> - 2016-03-16 16:09 -0700
                Hot-swap-ability of PS/2 devices (Was: Cursor while booting) gazelle@shell.xmission.com (Kenny McCormack) - 2016-03-17 00:31 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Riches <spamtrap42@jacob21819.net> - 2016-03-17 01:10 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-17 05:11 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Heller <heller@deepsoft.com> - 2016-03-16 20:54 -0500
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-17 05:13 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Keith Keller <kkeller-usenet@wombat.san-francisco.ca.us> - 2016-03-17 09:37 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-17 16:42 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2016-03-17 10:02 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) "Carlos E.R." <robin_listas@invalid.es> - 2016-03-17 20:11 +0100
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-18 01:55 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Riches <spamtrap42@jacob21819.net> - 2016-03-18 03:21 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) The Natural Philosopher <tnp@invalid.invalid> - 2016-03-18 12:10 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-18 15:33 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) "Carlos E.R." <robin_listas@invalid.es> - 2016-03-18 20:21 +0100
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-17 19:14 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2016-03-17 13:03 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-18 01:57 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2016-03-17 19:11 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Heller <heller@deepsoft.com> - 2016-03-17 14:30 -0500
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Keith Keller <kkeller-usenet@wombat.san-francisco.ca.us> - 2016-03-17 14:59 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Heller <heller@deepsoft.com> - 2016-03-17 18:16 -0500
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Keith Keller <kkeller-usenet@wombat.san-francisco.ca.us> - 2016-03-18 11:07 -0700
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Heller <heller@deepsoft.com> - 2016-03-18 13:49 -0500
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2016-03-18 22:13 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-18 19:55 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Robert Heller <heller@deepsoft.com> - 2016-03-18 15:13 -0500
                Re: Hot-swap-ability of PS/2 devices Andreas Kohlbach <march.10.ankman@spamgourmet.net> - 2016-03-18 14:35 -0400
                Re: Cursor while booting Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-03-17 13:31 +0100
                Re: Cursor while booting William Unruh <unruh@invalid.ca> - 2016-03-17 15:04 +0000
                Hot-swap-ability of PS/2 devices (Was: Cursor while booting) gazelle@shell.xmission.com (Kenny McCormack) - 2016-03-17 00:33 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) William Unruh <unruh@invalid.ca> - 2016-03-17 05:09 +0000
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Aragorn <thorongil@telenet.be.invalid> - 2016-03-17 14:15 +0100
                Re: Hot-swap-ability of PS/2 devices (Was: Cursor while booting) Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-03-17 15:05 +0100
      Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-15 02:49 -0700
        Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-15 02:57 -0700
  Re: Cursor while booting Teemu Likonen <tlikonen@iki.fi> - 2016-03-13 11:36 +0200
    Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-15 02:47 -0700
      Re: Cursor while booting William Unruh <unruh@invalid.ca> - 2016-03-15 19:45 +0000
    Re: Cursor while booting w4hw4h.hh@gmail.com - 2016-03-15 02:53 -0700
      Re: Cursor while booting The Natural Philosopher <tnp@invalid.invalid> - 2016-03-15 10:02 +0000
  Re: Cursor while booting Chick Tower <c.tower@deadspam.com> - 2016-03-15 16:52 +0000

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