The TTS coil can transmit data -- remember that the Touchstone 2 and the Touchpad Touchstones are able to transmit their station identifier to the device, which the device (at least the Touchpad, I don't know if it was implemented for Veer/Pre3) uses to relaunch whatever app was running the last time it was on that Touchstone in exhibition mode. It also transmits the bluetooth pairing information, so you don't need to enter anything other than confirming the connection if it's the first time the two have met (at least on the webOS 3 side)
Originally Posted by Preemptive
TTS did have file transfer ability in development, but that may well have been via the bluetooth link, as the TTS link itself is probably extremely short range and extremely slow. I dug around thru the TTS binaries once, and found the service calls for that stuff, but I was never able to figure out if there was enough implemented to get it to do anything.
The hardware involved is custom hardware, called "A6", I think I read somewhere that it was TI produced under a different name, and possibly had custom changes that HP did.
It also predated the widespread usage of NFC in cell devices.