Fax hard to operate. In 1966, Xerox released the Magnafax Telecopiers, a smaller, 46-pound facsimile machine. This unit was far easier to operate and could be connected to any standard telephone line. This machine was capable of transmitting a letter-sized document in about six minutes. The first sub-minute, digital fax machine was developed by Dacom, which built on digital data compression technology originally developed at Lockheed for satellite communication. By the late 1970s, many companies around the world (especially Japanese firms) had entered the fax market. Very shortly after this, a new wave of more compact, faster and efficient fax machines
Fax 2020. There are several indicators of fax capabilities: group, class, data transmission rate, and conformance with ITU-T (formerly CCITT) recommendations. Since the 1968 Carterphone decision, most fax machines have been designed to connect to standard PSTN lines and telephone numbers. Group 1 and 2 faxes are sent in the same manner as a frame of analog television, with each scanned line transmitted as a continuous analog signal. Horizontal resolution depended upon the quality of the scanner, transmission line, and the printer. Analog fax machines are obsolete and no longer manufactured. ITU-T Recommendations T.2 and T.3 were withdrawn as obsolete in