Abstract: A sequence of data groups are modulated at a central location and coupled to a telephone line in response to a call-up signal. The sequence is transmitted through the telephone lines to a remote computer. The computer receives the signals, demodulates them, and couples them to a moemory. The data is stored at a particular address, and in coupling the data to the memory, the computer checks a flag at that address to determine whether the data has already been written over. When the flags indicate that the data received corresponds to data already written over, it signals the end of a transmission. The data stored in the memory can be accessed by an operator using input controls.