A thorough revision of Schwaderer's Digital Communications covering the use of DOS 3.1 and 4.0 in networks and multitasking, 2400 Baud modems, and mainframe to micro communications. The book is structured to examine each communications discipline independently, allowing the reader to master specific concepts before proceeding to the next topic. Covered are modem, modem cable, and communication protocols, with a presentation of a systems perspective of how communications hardware works, and how to write interpreted BASIC communications programs that process data at a good 120 characters per second, and which, when compiled, can run over three times faster.