At 12:36 PM 5/21/01 -0400, you wrote:

>Has anyone heard of the CrossPad? It was a product from Cross, the pen
>company, that IBM was a major part of. It was basically a regular pad of
>paper with a radio receiver of some sort, and a radio transmitter in a
>special pen, that would digitize a good number of pages of written
>information.

Yes, I've seen them at CompUSA. Was thinking of buying one, but
unfortunately they don't seem to be pressure sensitive (so you can draw
and (optionally) have the line width vary with how hard you are pressing
the pen, for example), assuming the program you are using supports that
function.

>Many sources online say that then pen transmits "Pen stroke information"
>wirelessly, but how would the pen know its absolute position relative to the
>page? I'm thinking that there's some sort of triangulation going on here
>with signal strength.

Same principle as a digitizer tablet. A grid of X-Y wires and an RF source
or receiver in the pen or touch-screen type switches and a stylus.

>Does anyone have any idea as to where I can find a more in-depth discussion
>as to how this thing really works? I think it's really interesting, and
>would probably be even more interesting to try and duplicate.

Do a search on digitizer tablets, or graphics tablets they are common in the
CAD world. The part that moves is a "stylus" or a "puck". You can get
Autocad overlays that have scores of commands on them, and some of the pucks
have a ton of keys. Eg. Summmagraphics, Wacom. They are often available
cheap used without drivers etc.

Best regards,

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu