JOHN C GRAHAM
Broker in Marlboro, MA

4680788, Jul 14, 1987

Aug 31, 1983

6/528566

Craig A. Cordeiro - Westford MA
John P. Graham - Marlboro MA

Data General Corporation - Westboro MA

H04M 1100

379 93

A control and switching device which links a remote terminal by modems over telephone lines to a local central processing unit (CPU) and a local computer console terminal is disclosed. The device, which is coupled by separate lines to the modem at the local site, the local console and the TTY and ASYNC ports of the CPU, includes a microprocessor, a memory, logic circuits and a switch assembly. The switch assembly includes first, second and third switches which are interlocked and which allow three different levels of remote access of the remote terminal. When the first switch is depressed, the device is powered down, the remote terminal has no access to either the TTY or ASYNC ports of the CPU and the local console is hardwired through the device to the TTY port of the CPU. When the second switch is depressed, the local console is hardwired to the TTY port of the CPU and the remote terminal is electrically connected to the ASYNC port of the CPU. When the third switch is depressed, the local console and the remote terminal both have access to either the TTY port of the ASYNC port of the CPU.