23. A combination as in claim 13, wherein said input-output equipment comprises an electronic typewriter including a keyboard and a printer, a command decoder enabled by said selector bus for responding to signals supplied thereto via said command bus, key encoding means connected to the keyboard of said electrical typewriter, and gate means selectively enabled by said command decoder for energizing said input bus with the output of said key encoding means.
23. A combination as in claim 13, wherein said input-output equipment comprises an electronic typewriter including a keyboard and a printer, a command decoder enabled by said selector bus for responding to signals supplied thereto via said command bus, key encoding means connected to the keyboard of said electrical typewriter, and gate means selectively enabled by said command decoder for energizing said input bus with the output of said key encoding means. 24. A combination as in claim 23, wherein said input-output equipment further comprises additional decoder means selectively energized by said command decoder for responding to signals present on said output bus by causing printing at said electrical typewriter.