DVI Dongle / Cable for Suspend Mode

[Wilhelm Lehmann]

Hi all,

I was wondering if anyone has had any experience with DVI-I monitors /
signals.

I am trying to make a dongle or cable that can put the DVI monitor in
suspend mode (or DPMS off)

from the DVI specs ( http://www.ddwg.org ) I see on page 19 there is an
"Active-Off Power State" and states that the monitor can leave this state
(ie switch on) when "The DDC +5 volt signal is removed"

I take it to put the monitor into this state you have to apply the DDC 5+
Volt ?

Page 23 (signal list) there is a +5V Power signal, but what is this ? Is
this what I am looking for ?

On the old Analouge VGA monitors I achieved switch off / on by cutting the
Sync line with a relay. The monitor then says "no signal" and goes into
power save mode.

If I can put the monitor in suspend mode by cuting a single line, which line
will be best ? Maybe the DDC Data ? The pdf also states the monitor should
considder "no signal" when the freq is wrong ?

Any help would be appreciated

Just a note on why ....
Public Computer access is needed, where the need exists to limit time spend
on the computer but disabling mouse / keyboard etc is tricky, hardware wise
as the pc's sometimes hangs when the kb / mouse signals are interrupted,
software can be bypassed, so the easiest is switch the screen off, and
aparently the screens will last longer if you just put them in suspend mode.

Regards

Wilhelm

 

[kmillar]

You say 'software can be bypassed' but not if you configure the pc
correctly.
Using a kernel mode filter driver on the keyb and mouse would work, the
driver can't be unloaded by the user so they can't bypass it.

 

[Michael A. Terrell]

Wilhelm Lehmann wrote:

Just a note on why ....
Public Computer access is needed, where the need exists to limit time spend
on the computer but disabling mouse / keyboard etc is tricky, hardware wise
as the pc's sometimes hangs when the kb / mouse signals are interrupted,
software can be bypassed, so the easiest is switch the screen off, and
aparently the screens will last longer if you just put them in suspend mode.

Regards

Wilhelm

There is software used by libraries to limit the access time. The
local library system gives you 30 minute blocks, up to 2 hours a person
on slow days. If no one is waiting when your 30 minutes are up a message
pops up 5 minutes before your time is up to tell you that you have been
extended another 30 minutes. To use the system you give them your first
name, and they give you a four digit PIN number and tell you which
computer to use. It works fairly well even though the librarians are
not IT types.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida

 

[Wilhelm Lehmann]

Hi,

Thanks for the comments, but maybe I should add...
I developed a Smartcard system based on the Siemens SLE4442 card, that is a
hardware control.

This is after running public machinces since 1997, and sorry to say software
is NO good. You show me "perfect" software, we install it on ten machines
and guaranteed in less than a month more than half the machines needs to be
reinstalled. If you beleive your software is foolproof, we are willing to
try it, but after almost 10 years I have lost a lot of faith in SW control,
(a quick check of our records show we tried 78 diffetent systems from
different vendors, and not one positive report.)

Especially when there are new high-end games on the machines.

Trust me, kids try EVERYTHING to get free time, and the creativity I've seen
here is amazing, from writing virus type software to crash the kernel, to
messing up XP so bad you can't fix it other than a reinstall.

For the most part, the attempts to "break" software systems, dont work, but
it breaks other things, and generally just create an admin hassle.

on our machines with the hardware systems, our maintenance is about 80%
lower than the software systems (We are still trying every new "claimed to
be foolproof" system, and spend thousands on license fees on products that
does not do the job well.)

The hardware "cut" still works best, and I was just looking to modify our
already working system (on analouge VGA) to the new DVI technology.

Wilhelm


"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:43014226.BF77E070@earthlink.net...

Wilhelm Lehmann wrote:

Just a note on why ....
Public Computer access is needed, where the need exists to limit time
spend
on the computer but disabling mouse / keyboard etc is tricky, hardware
wise
as the pc's sometimes hangs when the kb / mouse signals are interrupted,
software can be bypassed, so the easiest is switch the screen off, and
aparently the screens will last longer if you just put them in suspend
mode.

Regards

Wilhelm


There is software used by libraries to limit the access time. The
local library system gives you 30 minute blocks, up to 2 hours a person
on slow days. If no one is waiting when your 30 minutes are up a message
pops up 5 minutes before your time is up to tell you that you have been
extended another 30 minutes. To use the system you give them your first
name, and they give you a four digit PIN number and tell you which
computer to use. It works fairly well even though the librarians are
not IT types.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida

 

[Ian Stirling]

Wilhelm Lehmann <wilhelm@iseek.co.za.i.dont.want.spam> wrote:

Hi,

Thanks for the comments, but maybe I should add...
I developed a Smartcard system based on the Siemens SLE4442 card, that is a
hardware control.

This is after running public machinces since 1997, and sorry to say software
is NO good. You show me "perfect" software, we install it on ten machines
and guaranteed in less than a month more than half the machines needs to be
reinstalled. If you beleive your software is foolproof, we are willing to
try it, but after almost 10 years I have lost a lot of faith in SW control,
(a quick check of our records show we tried 78 diffetent systems from
different vendors, and not one positive report.)

What sort of public access system?
To do what?
If it's just email/web, I'd install firefox, thunderbird on a linux system,
and set it up to automatically log the user out by killing the X server
at X minutes from the beginning. (giving a warning 1 min before).
If it could be done, simply running from CD may be an option.