Telephonic communications – Telephone line or system combined with diverse electrical... – Having transmission of a digital message signal over a...
Patent
1985-04-24
1988-08-09
Cangialosi, Salvatore
Telephonic communications
Telephone line or system combined with diverse electrical...
Having transmission of a digital message signal over a...
380 23, 380 25, H04L 900
Patent
active
047633514
ABSTRACT:
A computer security system employs a first telephone line for controlling a security unit which connects a second telephone line to the computer. Each authorized user must have a user security unit generating a control signal, such as an audio signal modulated by a pulse signal having a selectable pulse frequency, pulse duration and/or duration between pulses.
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Coleman Kevin G.
Lipscher Bernard N.
Cangialosi Salvatore
Lewis Aaron J.
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