The present invention provides shared communication medium capability to the plethora of computer devices, like the PCCAs, that normally are able to communicate with other devices via dedicated point-to-point links, e.g., via the practically universal RS-232 ports. It allows the sharing of the communication medium in a dynamic fashion depending on the instantaneous traffic demands by the various communicating devices. It further allows the emulation of point-to-point links over the shared communications medium in such a way that applications running on a PCCA use the shared medium transparently. Thus, this invention enables applications designed to operate over a point-to-point connection to operate over the shared medium without any modifications of the applications or the point-to-point devices. It enables the shared medium communications and dynamic communication resource allocation by using a device's I/O ports designed for point-to-point communications with dedicated communication resource allocation.