Abstract: A computer operated telephone dialing system has a program that selects a telephone number from a directory of names and corresponding telephone numbers. The program sends an off-hook instruction and a select flag to the computer's printer port, followed by a hexidecimal code sequence representing digits of the telephone number. A dialing circuit coupled to said printer port is activated by the select flag and, in response to the hexidecimal code sequence, provides DTMF dialing signals to telephone lines. The program then sends an on-hook signal, allowing a telephone handset to be used.