Data communication apparatus
Data communication apparatus including volatile and non-volatile
Data communication method and apparatus including volatile and n
Data storage apparatus
Data transmission apparatus having abbreviated dialing function
Deformable membrane keypad assembly for public telephones
Detecting whether a telephone line has been disconnected
Detection of both voice and tones using Goertzel filters
Detection of multifrequency tone signals
Determining the manner in which the wires connecting to a base s
Device and method for cleaning telephone number list
Device for automatically identifying DTMF and FSK for caller ID
Device for detecting DTMF tones
Device for detecting telephone line seizure
Device for detecting tones on telephone lines
Device for identifying line reversal/ringing signal of a telepho
Device for indicating a call to an absent subscriber
Device for setting and tone dialing a single telephone number
Devices, software and methods for passing DTMF signals under...
Dial information storing and redialing method for use in a telep