Abstract: A computer peripheral device for reading and writing cards conforming to the Personal Computer Memory Card International Association (PCMCIA) standard using a computer system equipped with a Small Computer Systems Interface (SCSI) bus. The device includes an Application Specific Integrated Circuit (ASIC), a gate array, a microprocessor unit, and a PC card interface unit. The PC card interface unit consists of a pair of latches, a bus transceiver, and a tri-state buffer. Data is transferred at high speed using a commercially available integrated circuit in a configuration in which the card is connected to the integrated circuit as if it were a random access memory buffer in a hard disk drive. Provision is made for automatically identifying the type of card inserted. Card slots are provided for two cards: one Type II card and one Type III card. Additional physical support is given to the card connector guides to prevent reverse card insertion.