DSRVF- PSU -AA Mini-exchange is a simple, inexpensive communications link for up to eight asynchronous devices within a range of 200 feet. It provides facilities for file and document transfer among Professionals and other Digital personal computers, queuing and allocating for shared devices such as letter-qual- ity printers or DSRVF- PSU modems, and communications with DSRVF- PSU RS232 C/423 compatible devices or non-Digital personal - - computers. Devices communicate at speeds ranging from 300 to 19,200 baud. Mini-exchange DSRVF- PSU is a microprocessor-based, automatic port-selection device with point-to-point circuit switching. Software support for Mini-exchange is provided as part of DSRVF- PSU/Communications and the asynchronous com- munications packages offered on Digital's other personal computers.