two - s into shuttle carrier aircraft. the next version, the - , holds approximately passengers and has a range of about nautical miles ( kilometers). in , two - bs were modified to serve as air force one and replaced the vc- s ( s) that served as the presidential airplane for nearly years. the - has...
slower. ironically, the transition to push button phones resulted in the switch from digital to analogue dtmf (touch tone) local loop signalling. nearly all landline phones now use analogue dtmf to the local exchange. — preceding unsigned comment added by . . ( talk ) : , august (utc) external links modified...