Using operating system routines for control and I/O applications

In the present day industrial environment, microcomputers such as IBM PC or Apple Macintosh have become very handy tools and subsystems for control and automation. Most of the software routines are written in higher level and transportable languages such as C or Pascal. Most of these microcomputers are networked together and the intelligence is shared to perform several other tasks, including task distributions. Many times, data needs to be entered into host system and is to be examined. Similarly, many times data need to be displayed on to the terminal for examination and further action. These operations involve some of the built in input/output functions of host system under consideration. Fortunately, the operating system of the host computer contains some of the I/O routines written in assembly and optimized for performance. A knowledge about these routines and how to use them with other software modules will greatly help utilization of these computers as host systems. We present some of the most widely used I/O routines for the IBM PC family of computers and case studies involving these built in routines. We also present some of the applications involving these routines which will help in the industrial use of these systems as host computers.<>