Fax July 1996. A major breakthrough in the development of the modern facsimile system was the result of digital technology, where the analog signal from scanners was digitized and then compressed, resulting in the ability to transmit high rates of data across standard phone lines. The first digital fax machine was the Dacom Rapidfax first sold in late 1960s, which incorporated digital data compression technology developed by Lockheed for transmission of images from satellites. Group 3 and 4 faxes are digital formats, and take advantage of digital compression methods to greatly reduce transmission times. Fax Over IP (FoIP) can transmit and
Black fax Black fax The term black fax refers to a prank fax transmission, consisting of one or more pages entirely filled with a uniform black tone. The sender's intention is generally to use up as much of the recipient's fax ink, toner, or thermal paper as possible, thus costing the recipient money and/or denying the recipient use of their own machine (this is similar to computer-based denial of service attacks). This is made easier because the fax transmission protocols compress the solid black image very well, so a very short fax call can produce many pages. Black faxes have been used