One mouse click, 2 PC's

Search under the topic "KVM switch". Normally they are meant to switch a device such as a mouse between different PCs but maybe there are some that allow parallel operation.

Even if you succeed with the wiring the sequence start isn't going to be that exact as the mouse is a polled device. Art

Actually, it isn't.

What do you consider "exactly" to mean?

What do you consider that "sequence" to be?

Better to synch the clocks on both units and use an applet to *start* the desired process at the same time point.

Mice are polled devices.

Do not think that can be done at *exactly* the same time, as the mouse is clocked by its computer and the clocks are NOT synchronized and may be pseudo-randumb due to spread-spectrum design.

...then add a zero!

AlwaysWrong. PS/2 mice use an interrupt. You big dummy.

You need basic continuity testing aptitude.

Correct.

He cannot guarantee or count on getting any resultant action be timed exactly together. There will be a number for maximum delay between the two events. It will be a worst case add-up of the two periods which the mouse port or USB-to-mouse port get polled at.

I like this approach!! Maybe even synch it to GPS or something...?

I know better than to ask why the OP want's to mouse-click two computers simultaneously!! But I must admit, I am just a tiny bit curious..... :)

Do interrupts not also get polled in cyclic fashion? Can you guarantee that both machines will poll their respective interrupts at the same moment?

When was the last time you saw a new PC or laptop that had a PS/2 mouse port? They do, but more often, they are made without them at all.

There are USB mice that plug into USB ports, and no PS/2 port is anywhere to be found. Those to are polled, and any such polling would be asynchronous with a separate device not triggered by the same clock.

You might think it worked "at the same time" but it in fact cannot be. There will always be some difference.

He is probably attempting to do some kind of lame "benchmark" between the two. That too is sad.

Define "exactly the same time" more clearly. The answer is yes, there are ways...

Also does it have to be a mouse click, or can it be some other type of signal? What are you controlling?

On Mon, 14 Jun 2010 04:59:42 -0700, Archimedes' Lever wibbled:

All of this is utterly irrelevant when compared to the OS scheduling quantum (typically between 10mS to 1mS), assuming the OP is running the test systems on regular machines and not some fancy realtime bit of hardware.

Anyway, back to the original point - I would have said time based would be easier - have the button "clicked" at a fixed time and time lock the machines using NTP.

Or have a trivial network listener do the "clicking" and use a script on one to send the network signal to start to both machines from a script.

For the most part, if he had told us what the circumstance was, any one of us could have delivered a more appropriate response. In one view, one person and two mice could be 'clicked' 'simultaneously', FAIAP. In another, if he really needs more simultaneous synchronization than he himself could bring with two mice, then reliance on raw synchronization that falls inside your timing region may not be enough either. So, yeah, more would be needed.

Generally the lay person would not see that as a difference, and if his application requires time stamps or other real time function, he would need something more appropriate, like two systems integrated into a chassis, being triggered by a third device installed into each of those two systems. Even then there can be latencies between pieces of gear, which have to be 'calibrated' against in the individual components.

This pretty interesting considering that the systems I currently plan use a 10Mhz source and two GPS fed 10Mhz "switches" that then feed all the remaining gear in the receiver system, keeping them all synch'd up. The rest is just standard network switch gear. Fire up the analyzer though and see that we know how to make the 'eye' look real nice.

Fun piecing together millions of dollars worth of equipment and watching that and five hundred or so wires and cables come together to allow a high bandwidth channel to the world, to be placed anywhere in the world.

Only if your net cards are set to NEVER time out and sleep. Many do, and windows uses it, set default to sleep after a certain period. There are latencies, just none that should concern someone that asked how to "see" button clicks from the cable end.

Why don't you find out how it is a tertiary function now, UNDER the PCI bus, and get back to me when you know what the f*ck is going on in a modern system.