Shields for electronic components with ready access to shielded components
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System for downloading program code to a microprocessor operative as a slave to a master microprocessor
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Flexible interface system for interfacing different complements of port circuits to a pcm telephony switching system
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Expanding switching capability of a time division communication system by multiplexing groups of circuits into successions
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Time division multiplex switching system for interconnecting telephone circuits which operate in accordance with different signalling systems and call formats
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Time division multiplex (TDM) switching system especially for pulse code modulated (PCM) telephony signals
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Key telephone system providing selection of key or PBX operational modes
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Ring trip detection system
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Communications switching system
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Ring trip detection system
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System for the testing of telephone switching systems
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Timing signal generation and distribution system for TDM telecommunications systems
