how does a monitor act as an interface?

[watdahel]

I read PC monitors can transmit data off it's screen. I've seen data watches where you hold the watch up against the monitor and the watch automatically syncs with the PC. How is this done?

 

[everman]

The thing with the watch simply reads barcodes displayed on the screen to transmit data.

 

[Smilin]

Those watches are pretty much just getting some form of binary communication from the flashing images on the monitor. They can't really "see" the monitor - only enough to read light or dark. All you gotta do is turn a white square on and off real quick on the monitor and you can transmit data.

It's some cheesy 1980's technology. The've moved on to infrared or Wi-Fi or something these days I hope.


On a side note: As the scan lines go back and forth across your screen they tend to cause that flickering on the wall by the monitor. It's possible to reconstruct a monitor or TV image simply from the light flickering on the walls in a family living room. Scary NSA stuff.

 

[jarsoffart]

I have that watch! It is the Timex Ironman Datalink watch. Do you know why the software won't work in Windows 2000 or Windows XP? Someone told me it was a weird refresh rate problem. Anyone care to elaborate?

 

[zsouthboy]

Originally posted by: jarsoffart
I have that watch! It is the Timex Ironman Datalink watch. Do you know why the software won't work in Windows 2000 or Windows XP? Someone told me it was a weird refresh rate problem. Anyone care to elaborate?

You can run the program in compatibility mode for Win98 and it will work just fine

Thats what i do

<--- has the Ironman triathlon and the 150 datalink

EDIT: Forgot to say.... the fact that it works in compatiblity mode perfectly fine makes me think that Timex just wanted you to buy a new damn watch for you to get 2k/xp support(or the "notebook adapter" :disgust: )... :| for timex :/

 

[jarsoffart]

Originally posted by: zsouthboy

Originally posted by: jarsoffart
I have that watch! It is the Timex Ironman Datalink watch. Do you know why the software won't work in Windows 2000 or Windows XP? Someone told me it was a weird refresh rate problem. Anyone care to elaborate?

You can run the program in compatibility mode for Win98 and it will work just fine

Thats what i do

<--- has the Ironman triathlon and the 150 datalink

EDIT: Forgot to say.... the fact that it works in compatiblity mode perfectly fine makes me think that Timex just wanted you to buy a new damn watch for you to get 2k/xp support(or the "notebook adapter" :disgust: )... :| for timex :/

How do I run it in compatibility mode for Win98.

 

[zsouthboy]

Right click on the shortcut, hit properties, then click the "Compatibility" tab... check the box and select Windows 98..

 

[sxr7171]

Originally posted by: Smilin
Those watches are pretty much just getting some form of binary communication from the flashing images on the monitor. They can't really "see" the monitor - only enough to read light or dark. All you gotta do is turn a white square on and off real quick on the monitor and you can transmit data. It's some cheesy 1980's technology. The've moved on to infrared or Wi-Fi or something these days I hope. On a side note: As the scan lines go back and forth across your screen they tend to cause that flickering on the wall by the monitor. It's possible to reconstruct a monitor or TV image simply from the light flickering on the walls in a family living room. Scary NSA stuff.

I'm guessing this wouldn't work with an LCD screen because the refresh isn't tied to the actual signal right?

 

[zsouthboy]

It doesn't work on an LCD because of the way the LCD displays the image. No refresh

 

[Smilin]

No, that image capturing technique doesn't work on LCD's. Only CRT's.

There's plenty of other ways to eaves drop on someone's PC. This "strobe" technique is pretty new. The old way still works though: picking up an image from the EM radiation given off by a PC (like that given off by your ramdac for instance).