A debit card read/write controller. The controller comprises a microcontroller device, a read only memory, a dynamically random access memory and a read/write head for reading and writing onto a magnetic card media contained on a magnetic striped card. The microcontroller device includes an input capture port for storing data read from the card, and wherein the microcontroller device continually poles the input capture port for an event to occur. The entire read/write system can be integrated into one single chip. The steps for processing the signal, processing the signal, and writing to the stripes have also been disclosed. The steps generally include inserting the card into a card reader operatively associated with the MR read head and passing manually the stripe underneath the MR read head, and wherein the information on the magnetic card media is stored in the form of a plurality of magnetic flux reversals. Next, the magnetic flux reversal is detected by the MR head as the stripe moves under the MR head, an analog signal is generated, conditioned, amplified and converted to a square wave. The input capture port polls the microcontroller for a flux reversal contained on the stripe to occur, and thereafter stores the timing value in memory. The stored timing is converted to timing pulse width associated with zero/one, read from the magnetic stripe. The information is converted to the designated characters according to the ISO/IEC CD 7811. The security and authentication of the data can be checked. For the read/write process in manual mode, the write head and read head is placed 2 to 3 bits distance apart.