understanding hid proxkey II rfids

Hi guys,

the other day I bought a parallax 28440 rfid reader. I wanted to make a device that will unlock my door when I use an HID proxkey II which I have on my keychain for other reasons. I made a poor assumption that the 28440 would be able to read it, as it works on the same frequency (125khz). The way I understand it, "normal" rfids (i think it's the em4100's) work like this:

header(111111111)
10x 4bit data(w/ parity at the end of those 4 bits(e.g.10100))
4x column parity
footer(0)

all-in-all this is 64 bits of data being transmitted in order to send a 10 digit number. Now my questions:
1.can I communicate with the hid tag with a 28440? (can't hurt to ask)
2.what do those HID tags send that's so different?

seb

well, it was a pretty random question and I'm not surprised there are no answers. How can I figure this out, though? Can I hold such an rfid near my 28440 reader (to power it), and then attach a nearby coil to an oscilloscope and read those values?

seb

It is likely that the tag you have doesn't have the parity bits in the same place so your reader is rejecting it.
Try building your own reader:-
http://arduino.cc/playground/Main/DIYRFIDReader