Question for the PC guru's

[Bruce]

Thanks for all the replies.

Alain;

We're already breaking video, PS2, and USB connections. It works great as-is, but I would like to simplify the hardware.

Luciano;

This one looks interesting. Thanks. The only problem I see with this approach is that a user could re-enable mouse/keyboard wakeup options once logged in. If there were some way to disable all input peripherals by controlling a bus signal, that would be perfect

Darrel;

Good points. Thanks. I'll look into what happens in suspend/hibernate. I wonder if networked PC's will drop-off the network in suspended or hibernate?

[Luciano]

The only problem I see with this approach is that a user could re-enable mouse/keyboard wakeup
options once logged in. If there were some way to disable all input peripherals by
controlling a bus signal, that would be perfect.

Are the users administrators???

[Bruce]

Not every user will have admin rights,, so on a system with admin options it would work fine, but not on older operating systems like ME, 98, etc.

[Luciano]

@skimask

If you enable 'WAKE ON LAN' the users on the network will be able to wake up other PCs.

Example of command line freeware:
http://www.matcode.com/wol.htm

Best regards,

Luciano

[Bruce]

You've got IR badges?

Yes.

I take it that they shoot out an IR signal at regular intervals?

Yes. The IR badge system works perfectly already. What I'm looking for is some way to
eliminate several mechanical relays. If we can interface to the PC bus via a PCI or ISA
card slot, and disconnect/disable input hardware, we can drop most of the relays.

Physically switching input devices & video works fine, but if there's an easier way, which
requires < hardware, I'm all ears...;o}

[skimask]

Yes. The IR badge system works perfectly already. What I'm looking for is some way to eliminate several mechanical relays. If we can interface to the PC bus via a PCI or ISA card slot, and disconnect/disable input hardware, we can drop most of the relays.

There has to be a way to send the 'Sleep' and 'Wakeup' keyboard commands over the USB port, if in fact the keyboards are USB. Heck, even PS/2 should work.

[Bruce]

This device is invisible to the operating system. There is no communications between it and the PC.

[sayzer]

This device is invisible to the operating system. There is no communications between it and the PC.

And I guess no software intervention is desired nor is planned then.

I was thinking; a small program works in background listening to an interrupt on PCI bus; and when it happens, the software disables the selected peripherals. As far as I know, there are 256 interrupt options. I might be wrong.

Wouldn't this be an easier way?

I am no PC guru BTW.

[skimask]

Good points. Thanks. I'll look into what happens in suspend/hibernate. I wonder if networked PC's will drop-off the network in suspended or hibernate?

I've got a setting in my BIOS called 'WAKE ON LAN'. But, I'm not sure if that means 'WAKE up anytime you hear anything come across the RJ45 jack' or maybe 'WAKE whenever you see a packet with my MAC address come across', or what. Never tried it.
But I can tell you that my both of my laptop's, and 2 PC's (plus a Wii and 2 Axim's) maintain the same local IP on my local wireless using DHCP before and after using hibernate (memory dump to hard drive, system shut off) and/or standby (system shut off, but memory kept refreshed). But if I do a complete shutdown, yes, when they come back up, the IP is sometimes different than it was before.

I was thinking about the first post. You've got IR badges? I take it that they shoot out an IR signal at regular intervals? How about receiving that IR signal with a separate PIC and using that IR signal as a sort of 'CLEARWDT' in a program. The PIC doesn't get the IR signal and, if there is 5v on one of the hard drive power connectors, it kicks a relay which connects the power button, PC shuts down. Later, the IR signal returns, PIC sees it, check the 5v line on the power connector, kick the relay, PC powers up. Maybe 15 seconds before it shuts the PC down, it fires off a small beeper to warn that it's about to shut down the PC, in case the user is turned around talking to somebody or something like that.