Abstract: A method of inputting print-destined data in rewritable card read/write apparatuses of a card utilization system very conveniently. A message edited by a computer (20) for rewritable card users is stored in a memory (23) provided in association with a magnetic head energizing means (21; 5) of a rewritable card read/write apparatus by way of an external-input interface (6). A magnetic card having at least one magnetic track for storing the message is inserted in the above-mentioned rewritable card read/write apparatus to thereby create a message card carrying the message from the magnetic card.

Abstract: In a rewritable card read/write apparatus including a printing thermal head (11) for printing data thermally and a transporting mechanism for feeding a rewritable card (19) forwardly and backwardly so that the rewritable card (19) can pass by the thermal head (11), a method which allows the printed data to be erased within a short time with the thermal head (11) itself. A columnwise printed data erasing range (18) of a printed data area is designated for the card (19) inserted into the apparatus. The thermal head (11) is electrically energized successively at least in two serial cycles by changing over electric energy level at least from a first electric energy level in a first cycle to a second electric energy level in a second cycle.