Hello guys ! Here is used such telephone cards like this one here ... Sorry , not very good picture here ;-) ... In the middle of this plastic card /------------\ is a chip ... See this picture here : | | | | | | [1] [2] [3] [4] | | | | | | | | | | | | | ___ | | | | | | | | | | | | | | | | | [ Chip ] | ----- | | \ | | | \ \------------/ | | | | [5] [6] [7] [8] As you see this chip has 6 legs ... and telephone card has 8 connectors ... Only 6 are connected ... Has anyone ideas, how this card works ... i mean something like telephone card hardware tutorials or something ... I have some ideas ... There is a something : when disconnect connector number [8] then The machine can't decrement the money value in card ... maybe he reads the value.. then he decrement the value in card , then reads "the new value" and if comparing between the old and the new value are the same , then machine disconnects he's telephone line ... Ok ... this is only one point ... But i want to know how this tech. works ... Anything is welcome ... please ... BTW Don't put answers to here , please mail-to me : sagi@physic.ut.ee Kristian