The Washington Post Co. yesterday launched a new on-line information service that will provide quick computer access to the contents of The Washington Post and allow subscribers to talk to the newspaper and to each other.

The multimillion-dollar initiative, known as Digital Ink, marks what industry analysts said is one of the most ambitious efforts to date by a newspaper to enter the world of electronic information services. That field has attracted many eager entrants, but so far on-line newspapers have signed up relatively few readers or advertisers.

"We're not just going to replicate The Post newspaper," said Don Brazeal, Digital Ink's editor and publisher. He said the service also will offer "rich, deep databases that offer everything from tourism information to detailed information about schools."

To reach the Digital Ink service, subscribers will dial local telephone numbers, then link their computers to the service electronically.

People who sign up before Oct. 1 will pay $5 per month for five hours of on-line use. Beginning Jan. 1, the monthly price will be $9.95. Beyond five hours, the service will cost $2.95 per hour, or just less than five cents a minute.

Once connected, Digital Ink subscribers will be able to read the Post as early as midnight before the day of publication, receive stock quotes, mortgage rates and entertainment listings and search The Post's classified advertising as well as archives of past news articles dating to 1986. Each story retrieved from the archives will cost 50 cents.

Digital Ink also aims to create electronic "neighborhoods" throughout the region by letting local area governments and schools post information on the service for community interaction. By fall, Digital Ink hopes to include access to the Internet computer network, including the World Wide Web, a graphics-based part of the Internet.

"This launch opens a new era in The Post's history," said Donald E. Graham, chairman of The Washington Post Co. and publisher of The Post. "We expect the printed paper to be around for a long time, but Digital Ink has its own attractions and attractiveness. This new service extends The Post's traditional quality to the world of cyberspace. It significantly expands both the amount of information available and its ease of use."

The Post has chosen a different strategy than most newspapers. Other papers are offering their content through established on-line services such as America Online and Prodigy. The Post will try instead to foster a direct relationship with on-line subscribers, comparable to what it has with its newspaper subscribers.

The Post contracted with the Interchange Online Network of AT&T Corp. to provide the software and electronic distribution for Digital Ink. The Post chose Interchange, Digital Ink officials said, because it appeared to offer the best technology for designing an interactive newspaper that had attractive graphics and word search capabilities.

But the price of this choice is that subscribers must have comparatively powerful computers. The service initially will run only on Windows-based personal computers equipped with at least a 386 processor and eight megabytes of random-access memory. A 9600 bits-per-second modem also is required.

Gary Arlen, president of Arlen Communications Inc., a consulting firm in Bethesda, said the Interchange technology strategy still may not really set The Post apart. "I'm not sure what I've seen so far from Digital Ink is that different. Its chances are the same as every other one of these papers. The question is, will customers really want to read the paper this way?"

Efforts by a number of newspapers in the 1980s to transmit text and other material for display on TV sets failed to find an audience. In the 1990s, newspapers have been making another bid to go electronic through on-line services that deliver information over phone lines to personal computer screens.

This time they are armed with advances in technology that allow more visually compelling photographs and graphics, new word search capabilities and greater interaction among readers and newspaper staff.

The New York Times, Chicago Tribune and San Jose Mercury News already are available on the America Online computer service. The Los Angeles Times, Newsday, Houston Chronicle and Tampa Tribune are on the Prodigy service and the Detroit Free Press and Florida Today are on CompuServe. Excerpts from the Wall Street Journal are available on the Internet.

Publisher Brazeal said Digital Ink comes at a time when personal computers and information services have become mass-market consumer items. In the metropolitan Washington area, 63 percent of adults own a PC at home or use one at work, while more than 50 percent own a home computer. Nearly 60 percent of area residents subscribe to The Post, the highest penetration rate of a newspaper in a U.S. metropolitan area.

The Post Co. plans an aggressive marketing campaign for Digital Ink, including wide distribution of free floppy disks containing the service's software (potential subscribers can call 1-800-510-5104).

Digital Ink's launch comes after a bumpy year that included an ownership switch at Interchange and troubles during a eight-month market trial of the software. AT&T purchased Interchange from Ziff Davis Inc. in December, which helped delayed the launch date for the service from the fourth quarter of 1994.

CAPTION: WHAT IS DIGITAL INK?

Digital Ink provides an electronic version of the newspaper, many new features such as a guide to the museums on the Mall or restaurants in Washington, discussion groups for readers to talk back to The Post or debate issues in the news, and areas where local schools and civic groups can post their own information. Users will be able to read stories from back issues of the paper, search The Post's classifieds ads and talk to each other. Digital Ink is now available for subscription. In the Washington area it will be reachable with a local phone call; around the country and in many foreign capitals, it will be accessible through AT&T's Interchange on-line network. This icon at the end of Post stories will alert readers to related information available only on Digital Ink.

This is Digital Ink's front page, with a table of contents running down the right-hand side. A click of the mouse on any item listed here will take the reader directly to that story or section.

Custom allows users to directly access their favorite parts of the service, so users are only one click away when they sign on.

This directory of services shows other features of the Interchange on-line service, some available for no additional cost to Digital Ink subscribers, some requiring an additional fee.

Mail and Updates Each user will have an e-mail address, with full Internet access planned for this fall. The updates feature allows users to automatically collect items of special interest to them in a personal folder. For example, a user could ask the system to save each day's stories on the Orioles, a stock quote or the latest additions to a Digital Ink discussion group.

Allows users to permanently save any file on their own computer.

Allows users to search by topic.

Reference Desk includes searchable archives of Post articles and "Today's Paper," another way to read the most current stories.