Summary

Sendata series 700 modem for use with conventional telephone handsets; comprises microphone unit joined by flexible coupling to speaker unit, with rubber surrounds on each to attenuate external noise. Full duplex 300 bits per second transmission and reception accepted by this type of modem. Made by Electromed in Victoria, Australia about 1975.

The curator, who acquired this item, stated:
'These acoustic coupled devices were very difficult to use; any loud noise in the vicinity (dog barking, door slamming) caused massive data blockages. Yet the urge to telecompute was so great that these disadvantages were overlooked. A problem with the newer telecom receivers made in the late 1970s was that the hand piece was unsuitable for use with acoustic modems. Telecom somewhat airily remarked that they did not consider this important. When direct connection modems became available, the rush to replace the old acoustic units was immediate. The acoustic units therefore represent a highly transitional stage in the spread of telecomputing.'

Physical Description

Each unit comprises comprises microphone unit joined by flexible coupling to speaker unit, with rubber surrounds on each to attenuate external noise.

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