I transferred files from my commodore 64 to PC by connecting the C64 modem phone line to the PC phone line and powering up by connecting both in parallel with the actual phone line to get the dial tone one modem needed and then by dialing the Telstra number check to trick the dialing modem to think it had successfully dialed a number and get the receiving modem to pick up on the telstra number call back test and to maintain the required Line voltage during the transfer..