orded, a sender can transmit the same information to several re- ceivers one after another. The information to be sent is first stored in a memory and then transmitted in turn to each address. In data processing, facsimile machines are being used as input/output ter- minals. Facsimile machines are expected to be used increasingly in office automation, especially in image communications. 4.4.2 Image Resolution Resolution is an important factor in determining the size of the smallest characters that can legibly be scanned and printed, as well as the sharpness or quality of the facsimile output. Both horizontal and vertical resolution parameters are included. Horizontal indicates how many times a scanner or printing element stops along the width of the page. Vertical refers to how many times the scanner or print- ing element stops or marks down the length of a page. Generally, horizontal parameters are larger than vertical factors, although in many common cases the two may be equal. One scan line consists TERMINAL TECHNOLOGY 67 of one row of picture elements plus one blank row before the next row of picture elements. A resolution of 200 1pi horizontal by 200 1pi vertical will have picture elements of 1/200th of an inch each. It takes a combination of the horizontal and vertical scanning "stops" to complete the construction of a facsimile image. It should also be noted that resolution is related to transmission time; decreasing the line resolution will decrease the time and cost necessary to transmit the document. Considering today's facsimile techniques (including complex technical factors related to line width, scan sweeps per second, document feed speed, etc.), the use of a system engineered to work with 1/16" high characters will require a higher resolution, and increase the time and communications ex- pense to deliver a document. The time required will be three to four times that associated with 1/8" high characters. The transmission of tone shades requires the scanning of a large number of points or elements. T