<communications> A term applied by Western Union Telegraph Company to teletypewriters that are not part of a multiplex system. They usually provided for alternate transmission in both directions. If working simplex or half-duplex, what was keyed in at the keyboard would be typed out at the printing portion. If working full-duplex, sending would be blind as the printing portion was being used only for reception.
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Nearby terms: Simple Object Access Protocol « simplex « simplex method « simplex printer » SIMPL/I » Simplified Multicast Routing Protocol » SIMPL-T