ADIC Added to Russell Indexes.

REDMOND, Wash.--(BUSINESS WIRE)--July 8, 1999--

Advanced Digital Information Corporation (Nasdaq:ADIC) announced today that is has been added to the Russell 3000(R) and Russell 2000(R) indexes, two of the leading indexes used to measure the performance of the largest U.S. companies based on total market capitalization.

The Russell indexes serve among the leading benchmarks for investment evaluation, and, according to the Frank Russell Company, more than $145 billion are invested in funds that use the Russell indexes as investment models.

"We're excited to be recognized among the most valuable companies in the country," commented Peter van Oppen, ADIC Chairman and Chief Executive Officer. "ADIC's inclusion in the Russell indexes is one more indication of the importance that electronic information is assuming as the business community grapples with the problems and opportunities presented by the Internet explosion and the emergence of applications such as e-commerce. ADIC has grown into one of the leading providers of systems to manage and protect the data that increasingly runs the world's businesses."

Each year, on May 31, the Frank Russell Company compiles and ranks the 3,000 largest U.S. companies by market capitalization. The large cap Russell 1000(R) Index comprises the largest 1,000 companies in the ranking, while the Russell 2000(R) Index includes the 2,000 smaller cap members. The final listing is confirmed on June 30, and released in its entirety to the public on July 8. More information about the Russell indexes is available at www.russell.com.

About ADIC

With more than 40,000 automated tape libraries installed as well as a suite of innovative software solutions and Storage Area Networking (SAN) products, ADIC is a leading global provider in the growing market to manage and protect information in computer networks. Marketed under ADIC, ADIC/GRAU and OEM partner brands, including Dell, Exabyte and Unisys, the Company's automated tape libraries are available with DLTtape(TM), D2, half-inch, AIT, 4mm and 8mm tape technologies and are supported by leading backup and storage management software products for Windows NT, UNIX and MVS operating systems. The Company's own storage management tools include AMASS(R) direct data access software which provides network users shared access to information stored in automated libraries. A pioneer in marketing products for Storage Area Networks, ADIC offers Fibre Channel routers and tape libraries with direct Fibre Channel connectivity. Further product information is available via the Internet at www.adic.com.

ADIC is a trademark of Advanced Digital Information Corporation. DLTtape is a trademark of Quantum Corporation. Russell 3000, Russell 2000, and Russell 1000 are trademarks of the Frank Russell Company. All other product, trademark, company, or service names mentioned herein are the property of their respective owners.