Abstract: A computer system having a memory card for storing data that is capable of being removed and reinserted and also having the capability of safeguarding the data stored thereon. A passward is stored on the memory card. The memory card is set in a secure mode to prevent unauthorized access to the data stored on the memory card. Once the memory card is set in secure mode, it remains in secure mode, even when removed from the computer system and subsequently inserted back into that or another computer system. Access to the data is permitted when the memory card is set in secure mode only if a valid password is provided to the memory card.

Abstract: A control unit controls a data processing system port to communicate with different peripheral devices. The control unit determines the type of peripheral device that is being serviced and whether the port apparatus is transmitting or receiving data, and accordingly, activates a program to load a particular count into a counter. Upon reaching a specified count, the counter activates the control unit to control the sampling time of the incoming signal and to determine the interval of time or frequency of the transmitted data information signals.