A system comprising a media processing apparatus and a computer where the media processing apparatus emulates a mass storage device and interfaces with the computer is disclosed. In one embodiment the media processing apparatus appears to the computer as a Universal serial bus (USB) mass storage device, and the operating system (OS) on the computer, using its pre-installed USB mass storage device driver, establishes bi-directional communication channel with the media processing apparatus. Thus, the need to develop an OS specific kernel-mode device driver for the media processing apparatus is eliminated. The system may employ a proprietary communication protocol on the USB bus to send and receive data between the computer and the media processing apparatus. In one embodiment, the computer sends and receives data by executing read and write operations to sectors of the emulated USB mass storage device; while the media processing apparatus deciphers the read and write operations on emulated sectors and takes appropriate actions. User-mode applications on the computer and the media processing apparatus may employ Remote Procedure Call (RPC) mechanisms to issue commands and share their respective resources with each other.