Coming soon: a computer map of the world.The United States, Canada, Britain, and Australia are working on a joint project called the Digital Chart of the World (DCW). When it goes on sale next year, computer users will be able to see the coastlines, contours, major roads, railroads, and population centers of every nation on earth. One goal of the multinational project is to provide a base-line map for developers of geographic information systems (GIS). Thus, anyone from an Army general to a transportation executive could use DCW to find the most efficient trucking routes in a foreign country. Or they could add their own information or maps to the data already presented. The military used similar computer maps for planning in Operation Desert Storm, says David Danko, DCW project manager for the US Defense Mapping Agency, which is spearheading the US effort. The United Nations Food and Agriculture Organization wants a computerized map of Africa to study crops on the continent, he adds. The project's other goal is to develop a standard for GIS itself. That way, developers can build GIS products that will generate and accept a common mapping format. If the computer world accepts this standard, computer users should have an easier time using different GIS software on the same map. Four or perhaps five CD-ROMs - compact discs that "play" data instead of music - will hold the DCW. The map comes with software that allows users to make simple queries of the data and zoom in and out of maps. At a scale of 1:1 million, an inch equals about 16 miles. Paris will be the size of an old silver dollar, and New York City the size of a hand. The cost of the map could be about $100, Mr. Danko says.