Is the keyboard hot pluggable?

  • Thread starter Thread starter Peter Olcott
  • Start date Start date
While not a good idea, I've done it on about every system I've ever owned.
The current one falls out every few weeks or so, at which time I plug it
back in and go about my business.

The only thing that is noticeably different is that the typematic rate
changes, at least until the next boot.

I wouldn't recommend it, though.

Jon
Click to expand...

I have two Win9x systems connected to a passive KVM box. Whenever I
switch between them, the typematic settings are lost.

To work around this, I have a desktop shortcut which I access with
Ctrl_Alt_K and which executes the following command line:

C:\WINDOWS\COMMAND\MODE.COM con rate=32 delay=1

I don't know if a similar technique will work for Win2K and above.

- Franc Zabkar
 
Can the keyboard be safely unplugged, and plugged back in
with the power turned on?
Click to expand...

I have a passive KVM box that connects two computers to an old
AT-style keyboard. AFAICS, switching between PCs is akin to
hotplugging the keyboard. I've done this hundreds of times without
incident. I would think that a properly designed KVM box should make
the power contacts before making the signal contacts, as is the case
with USB, but my box appears to have only a simple multipole rotary
switch.

- Franc Zabkar
 
I have a passive KVM box that connects two computers to an old
AT-style keyboard. AFAICS, switching between PCs is akin to
hotplugging the keyboard. I've done this hundreds of times without
incident. I would think that a properly designed KVM box should make
the power contacts before making the signal contacts, as is the case
with USB, but my box appears to have only a simple multipole rotary
switch.
Click to expand...

ISTR AT style keyboards should be hot pluggable, in practice even
if not by design (similar to serial and parallel ports). It is
PS/2 ports that are potentially troublesome. Even then, many
mobo/keyboard combinations are perfectly happy with hot-plugging,
it is just there is no way of knowing if yours happens to be one
of them before trying it, by which time it may be too late.

Of course, I've no idea how this relates to the fact the two types
are electrically identical and you can easily adapt AT to PS/2 and
vice versa... the connections on an AT keyboard are standard 5-pin
DIN AFAIK, there's no differentiation in contact length. Maybe it
is simply standard practice that AT keyboard sockets have the
necessary protection in place.
 
"Franc Zabkar" wrote ,
"Jon Danniken" put finger to keyboard and composed:

I have two Win9x systems connected to a passive KVM box. Whenever I
switch between them, the typematic settings are lost.

To work around this, I have a desktop shortcut which I access with
Ctrl_Alt_K and which executes the following command line:

C:\WINDOWS\COMMAND\MODE.COM con rate=32 delay=1

I don't know if a similar technique will work for Win2K and above.
Click to expand...

Thanks, Franc, I'll give that a whirl the next time my cord becomes yanked.

Jon
 
Jon Danniken said:
"Franc Zabkar" wrote ,

Thanks, Franc, I'll give that a whirl the next time my
cord becomes yanked.

Jon
Click to expand...

The fact that the keyboard was not designed to be hot
pluggable was apparently the root cause of my problem. My
keyboard was destroyed. The PS2 port worked OK with another
keyboard, but, the optimal solution that I chose was to
switch to a hot pluggable USB keyboard. I have been using a
USB mouse for years.
 
Peter Olcott said:
Can the keyboard be safely unplugged, and plugged back in with the power
turned on?
Click to expand...

I do it all the time on both my computers with PS2 ports.
No problems whatsoever.
I would not hesitate to do it on a brand new computer.
 
Peter Olcott said:
Can the keyboard be safely unplugged, and plugged back in with the power
turned on?
Click to expand...

Yes. Well PS2 is for sure, I have done it on both my computers
with no problem.
Hard to see how any hard couldbe done
 
Lord Turkey Cough said:
I do it all the time on both my computers with PS2 ports.
No problems whatsoever.
I would not hesitate to do it on a brand new computer.
Click to expand...

It ruined my keyboard to I switched to a USB keyboard.
 
Peter Olcott said:
It ruined my keyboard to I switched to a USB keyboard.
Click to expand...

??? how can you ruin a keybooard?

All you are doing is plugging it it, ie giving it power, which is
the same as you so when ou power your computer up.

I fail to see how any device can not be hot pluggable, to be honest.
 
??? how can you ruin a keybooard?
Click to expand...

More likely he meant it ruined the keyboard port on the PC.
All you are doing is plugging it it, ie giving it power, which is
the same as you so when ou power your computer up.

I fail to see how any device can not be hot pluggable, to be honest.
Click to expand...

Plug is half way in... the 5v and data lines have made contact, but not
ground. All power is shunted through the data leads - *POP*
 
??? how can you ruin a keybooard?

All you are doing is plugging it it, ie giving it power, which is
the same as you so when ou power your computer up.

I fail to see how any device can not be hot pluggable, to be honest.
Click to expand...

Do you feel the same way about your video card, can it be
put in and taken out while the system is running?
 
Lord said:
??? how can you ruin a keybooard?

All you are doing is plugging it it, ie giving it power, which is
the same as you so when ou power your computer up.

I fail to see how any device can not be hot pluggable, to be honest.
Click to expand...

http://en.wikipedia.org/wiki/Hot_swap

Protocols that now support hot swapping include PC card, USB, FireWire,
Fibre Channel, SATA, SCSI and SAS.

Protocols that do not support hot swapping include PATA and PS/2

If you look closely at the connector design on hot swap components, some
pins may be longer than others. In the following example, the six ground
pins are longer than the others, and the ground pins make contact first.
Doing such things, is to prevent reverse potentials from appearing on data
pins. PS/2 has the pins all the same length, and any one could make contact
before the others.

http://www.shopaddonics.com/mmSHOPADDONICS/Images/AASA4PPC.gif

Even Firewire, although it is listed in the hot swap list above,
is not considered entirely safe by its user base. Experienced
users connect Firewire cabling, before powering up their system.

HTH,
Paul
 
Calab said:
More likely he meant it ruined the keyboard port on the PC.


Plug is half way in... the 5v and data lines have made contact, but not
ground. All power is shunted through the data leads - *POP*
Click to expand...

Even if that were true you could simply make the data connection shorter.
 
Paul said:
http://en.wikipedia.org/wiki/Hot_swap

Protocols that now support hot swapping include PC card, USB, FireWire,
Fibre Channel, SATA, SCSI and SAS.

Protocols that do not support hot swapping include PATA and PS/2

If you look closely at the connector design on hot swap components, some
pins may be longer than others. In the following example, the six ground
pins are longer than the others, and the ground pins make contact first.
Doing such things, is to prevent reverse potentials from appearing on data
pins. PS/2 has the pins all the same length, and any one could make
contact
before the others.
Click to expand...

Just made a comment about pin lengths before I read this.
It's prettty obvious really.
Anyhow I don't give a second thought to unplugging or swappinig keyboards
whilst powered up. I used to do it regularly.
5 volts is negligible, they have to cope with that anyway.

My USB2 digital TV stick won't work unless it is plugged in from
power up though, but I expect that is down to crap software.
 
Even if that were true you could simply make the data connection shorter.
Click to expand...


What do you mean "could"? You are suggesting the entire
world lop off the connectors and make some new proprietary
connector and solder it on?

However, in all fairness the ground should make contact
before anything else because the outer metal rim is grounded
as is the frame of the connector shell. It still doesn't
eliminate the chance of transient surges, basically what it
boils down to is that in this industry parts are designed as
cheaply as possible and that means that if something doesn't
"NEED" to be hot pluggable, if there's a way to save a penny
by not supporting it, you can bet someone didn't.
 
Just made a comment about pin lengths before I read this.
It's prettty obvious really.
Anyhow I don't give a second thought to unplugging or swappinig keyboards
whilst powered up. I used to do it regularly.
5 volts is negligible, they have to cope with that anyway.

My USB2 digital TV stick won't work unless it is plugged in from
power up though, but I expect that is down to crap software.
Click to expand...


This is a situation a bit like ESD damage. I mean you can
do it 100 times and have no problem, but that doesn't change
the fact that the 101st time you might have a problem
because it wasn't designed to accomodate this.
 
Just made a comment about pin lengths before I read this.
It's prettty obvious really.
Anyhow I don't give a second thought to unplugging or swappinig keyboards
whilst powered up. I used to do it regularly.
5 volts is negligible, they have to cope with that anyway.
Click to expand...

http://en.wikipedia.org/wiki/Latchup

"A latchup is the inadvertent creation of a low-impedance path between
the power supply rails of an electronic component, triggering a
parasitic structure, which then acts as a short circuit, disrupting
proper functioning of the part and possibly even leading to its
destruction due to overcurrent."

"It is possible to design chips that are latchup-resistant, where a
layer of insulating oxide (called a trench) surrounds both the NMOS
and the PMOS transistors. This breaks the parasitic SCR structure
between these transistors. Such parts are important in the cases where
the proper sequencing of power and signals cannot be guaranteed (e.g.,
in hot swap devices)."

- Franc Zabkar
 
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