A system for transmitting binary instruction or data words to or from a computer by control from a home base remote from the computer site, and characterized by the entry of signals into the computer or the extraction of signals from the computer performed by apparatus which directly connects to the computer console manual switches and indicator lights. A single telephone line forming two simultaneously active channels transmitting time-spaced pulses in opposite directions, by modems known in the art, is used as the communication link. A special purpose microcomputer directly connected to the main computer console acts figuratively to actuate the console push buttom switches in response to pulse train signals received from home base and representing single bits or multibit words. It returns to the home base a rapidly iterated and updated pulse train representative of the status of all console lights. The system includes another computer at the home base with a duplicate, reflective console like that of the main computer. The apparatus at the home base computer responds to binary messages to the main computer, due to actuation of the reflective console, with the same effect as if it were bing used and observed at the computer site.