A head assembly moving along a long side of a magnetic card, more than one magnetic head rotating in the head assembly for reading/writing data, a rotary transformer and a carriage with a card holding mechanism for keeping a card at a predefined position are provided in a card reader of the present invention. A rotating part of the rotary transformer in the head assembly receives and sends a signal to the magnetic head and a fixing part of the rotary transformer is connected to a reading/writing circuit. On the card of the present invention, which is usually rectangular, there are tracks defined by plural arcs. The arcs are on plural same-size circles whose centers are aligned on one line along the long side of the card. A magnetic card or an optical card can be used for the present invention.
