SIC 3572
COMPUTER STORAGE DEVICES



This classification covers establishments primarily engaged in manufacturing computer storage devices.

NAICS Code(s)

334112 (Computer Storage Device Manufacturing)

Industry Snapshot

The computer storage industry manufactures tape, magnetic, and optical storage and retrieval devices for computer systems. These products range from the common floppy and hard disk drives built into desktop computers to stand-alone storage management systems used in large enterprise networks.

Demand for storage capacity and performance has risen sharply, as microprocessors have grown faster, software applications have become more resource intensive, and network computing has become more pervasive. Attempts to harness processing power and offer users more features have made the typical new software application require vastly more storage space than earlier versions. On personal computers, storage needs have further evolved and multiplied because of expanding multimedia features and content, such as DVD movies and down-loadable music on the Internet. Meanwhile, corporate systems have had to cope with escalating storage and processing needs from internal users, as well as from the Internet.

Shipment values for computer storage devices and equipment, which totaled $9.0 billion in 2000, fell to $8.2 billion in 2001. At that time, some 66 companies competed in the domestic market. Despite the myriad forces stimulating demand for storage devices, the industry, like other computer hardware segments, has been hurt by fierce price competition. Such pressures have prompted significant consolidation within the industry and have brought cost cutting to the fore at several storage device companies. In addition to increased price competition, the market for storage devices was at the mercy of a weak economic climate in the early 2000s. This presented challenges across virtually every product segment in the computer industry, as manufacturers faced reduced spending and confidence levels in both the consumer and corporate sectors.

In the early 2000s, the industry continued to face both challenges and opportunities associated with storage outsourcing services, or so-called storage service providers (SSPs). Such Internet-based services offer storage space and management tools that clients can simply connect to and use, enabling companies to avoid purchasing and maintaining storage hardware and software themselves. In the early 2000s, the nascent SSP field was altering how storage devices are used and marketed. It also presented an opportunity for makers of storage equipment to branch into services. By 2001 telecommunication giants like WorldCom and AT&T were involved in this sector. Worldwide, IDC, a leader in technology intelligence and industry analysis, forecast spending on SSPs to increase from $153 million in 2000 to $10.7 billion in 2005, according to Computing Canada . This increase reflected a compound annual growth rate of 134 percent.

Organization and Structure

Most computer memory storage devices can be classified as either optical or magnetic. In addition to optical and magnetic storage, semiconductor memory chips that store data and programs in the form of digital impulses had gained recognition as a viable new technology by the early 1990s.

Magnetic Storage. Magnetic devices record information in the form of magnetized spots that represent a binary code—a series of digits represented by either 1 or 0. A magnetized head suspended slightly above the surface of a medium reads and writes information on the disk. To record information, electrical charges that register a pattern on the surface of the magnetically sensitive medium are delivered through the head. To read data, the same head detects and converts spots into electrical impulses. The data can be retained indefinitely, or erased and replaced with new magnetic spots.

The three primary classes of magnetic storage devices are hard disk drives, floppy disk drives, and magnetic tape machines. Magnetic tapes, which were once the most widely used method of computer memory storage, store data on 4-inch-wide or 8 millimeter tape coated with a magnetically sensitive compound. Tape units typically read and write at a rate of 183 to 722 kilobytes per second and can store more than 270 gigabytes. Some units, called autoloaders, combine several tape cartridges to maximize speed and capacity.

The advantage of magnetic tape storage is that massive quantities of information can be stored in a relatively compact space. Furthermore, tape devices have historically been the fastest method of reading and writing large amounts of data. The drawback of tape systems, however, is that the tape must be read from one end to the other in order to retrieve and store information. For this reason, magnetic tape is most often used to copy, or backup, large amounts of data stored on a network or mainframe system (or for other purposes in which stored data can be sequentially accessed). In 2001 about 705,700 magnetic tape storage components were shipped by U.S. manufacturers, valued at roughly $1.9 billion.

Floppy diskette drives read and write information to a single rotating disk that can be removed from the drive. They are used to transfer and temporarily store information on 3.5-inch or 5.25-inch diskettes. Floppy drive technology is essentially the same as that used in hard disk drives, but floppy disks are made of coated synthetic material rather than metal. Although some U.S. manufacturers produce floppy drives, the domestic magnetic drive industry emphasizes hard drive production.

A hard disk magnetic storage device resembles a stack of small metal plates that rotate at a constant speed. Between each plate, a magnetic head is positioned on an arm that sweeps across the disk's surface. Each plate is coated on both sides with a magnetically sensitive compound on which a head can read or write information. Every bit of information stored on the disks is accessible by the heads each time the stack rotates.

The advantage of hard drives is that they can quickly retrieve information nonsequentially. Furthermore, because they are compact, they make excellent storage devices for microcomputers. Disk drives with greater capacities are commonly used in workstations, minicomputers, local area networks (LANs), and mainframes. Hard drives for larger computer systems are generally 14-inch, 10-inch, or 8-inch drives. Microcomputers typically have 5.25-inch, 3.5-inch, 2.5-inch, or 1.8-inch drives. Smaller disks usually hold one to two megabytes of information.

Computers communicate, or interface, with disk drives through a controller. Most drives comply with high-performance interface standards, such as the Enhanced Small Drive Interface (ESDI), or the Small Computer Systems Interface (SCSI). SCSI drives are more easily integrated into other manufacturers' products; consequently, they are the most common type of drive.

Optical Storage. Compact Disc-Read Only Memory (CD-ROM) drives use laser beams to read information on a rotating synthetic disk. Most consumer disks are composed of three layers: an overcoat that protects the information on the disk; the dye layer, where the information is recorded as digital bits of information; and a mirrored base that reflects the laser back to its source.

CD-Write Once Read Many (CD-WORM) drives and discs also allow users to store their own information on a disc, though that data cannot be erased and replaced with new information. CD-Recordable (CD-R) is a write-once technology like the CD-WORM that has become one of the first of such devices to be priced within the consumer/small business market. Another optical storage option available in the early 2000s was the "erasable CD-ROM," which had the capability to rewrite or replace existing data. Finally, another optical storage device that began to gain popularity in the late 1990s was the DVD, or high-density compact disc. The drives and discs have more capacity to handle video with storage levels of 4.7 to 17 gigabytes. Conventional CD-ROMs used in most PCs have a capacity of roughly 650 megabytes.

The advantage of optical storage is that comparatively massive amounts of information can be inexpensively stored on a small, portable medium. Because a single CD can store up to 300,000 pages of information, CD-ROM is often used for storing such memory intensive applications as information databases or programs with elaborate graphics. The name and phone number of every household in the United States, for instance, was available on three CDs in 1997 for less than $100. The disadvantage of CD-ROM is that information retrieval is significantly slower than that of magnetic devices. Also, optical storage is relatively inflexible because it does not allow users to easily write and erase information.

Semiconductor Memory. Another form of computer storage is semiconductor memory chips called flash cards. Flash memory stores programs and data in the form of digital impulses. Data can be easily read, written, and erased on cards that hold two to four megabytes of data. The cards can be inserted and removed from a flash card slot just like a floppy diskette. Flash cards perform much faster than magnetic devices and require much less power to operate.

Because flash memory is nonvolatile and requires no moving parts, a user can turn off his computer, turn it back on later, and find himself at the same place he was when he powered down. Because of its advantages, flash memory technology is popular with manufacturers of notebook, pen-based, and hand-held computers. The Personal Computer Memory Card International Association (PCMCIA) represents the interests of this industry segment and strives to maintain manufacturing standards.

Competitive Structure. A multitude of different organizational structures is represented in the computer memory storage industry. The industry is highly fragmented and is characterized by technological volatility. Firms that do not develop and produce breakthrough products are often forced to compete in a high-volume, low-margin, commodity-like market environment. Leading firms, in contrast, can reap huge short-term profits as a result of innovation. These firms, though, must often risk large research and development expenditures to generate new technology for rapidly shifting, unpredictable markets.

Original equipment manufacturers, such as IBM and Hewlett-Packard, produce or purchase devices that are integrated into their own computers. Other large vendors, such as Seagate Technologies, produce devices that are installed in, or used with, other computer manufacturers' products. These companies tend to purchase few of their components from other companies. In contrast to the more vertically integrated companies just described, several companies utilize foreign manufacturers to produce their drives or to manufacture many of the components that go into their storage devices.

Background and Development

The punch card, the first storage mechanism used with a mechanical computer, was introduced by Herman Hollerith in 1886 to help the U.S. Bureau of the Census calculate demographic data. The punch card concept was actually developed by Charles Babbage and was demonstrated in his 1833 design of the Analytical Engine. Although Babbage's engine was never built, it provided a model for Hollerith and others. Punch cards allowed computer operators to automatically repeat arithmetic operations on numbers that were represented by holes punched into successive cards.

In 1944 IBM developed the first large-scale automatic digital computer, which was conceived by Howard H. Aiken of Harvard University. The Automatic Sequence Controlled Calculator (nicknamed the Mark I) utilized more than 750,000 parts and relied on punched cards and punched tape to store data. The device was used to compute ballistic data for defense purposes and could calculate three additions per second. In 1946 Bell Telephone Laboratories developed a similar computer that stored and read sequences of instructions on loops of paper tape.

The Electronic Numerical Integrator and Calculator (ENIAC), which was completed in 1945, stored numbers and computing instructions entirely by electronic circuits containing more than 18,000 vacuum tubes. Although ENIAC still used punched cards for input and output data, the computer could electronically store 20 numbers. The computer had to be programmed by tedious rewiring in order to accomplish different tasks. Despite its limitations, the computer was used until 1956.

During the mid-1940s researchers realized that a major hurdle in the advancement of computer technology was a lack of adequate resident memory storage capacity. During the 1940s and 1950s, four storage techniques were developed: acoustic delay lines, magnetic drums, electrostatic devices, and magnetic cores. Mathematician John von Neumann was one of the most influential developers of storage technology during this era.

The first magnetic core computer, the Whirlwind, was developed at the Massachusetts Institute of Technology in 1953. By the mid-1950s magnetic core memory had become the principal storage system. At this point, many companies realized that computer production and design had the potential to be a viable industry. IBM, Sperry, Rand, Burroughs, RCA, General Electric, and other companies quickly began introducing computers for a variety of commercial and institutional applications. By 1960 in fact approximately 5,000 stored-program computers were operating in the United States. Throughout the 1960s this number doubled every two to three years.

As the computer industry expanded during the 1960s and 1970s, the need for mass memory storage devices that could hold programs and backup data drove the development of a variety of mechanisms. Some of the most successful storage devices used magnetic "Winchester" technology. These devices, which were developed by IBM in 1956, evolved into what is now the magnetic hard disk drive.

The 1980s. During the 1980s the use of Winchester drives began to dominate the memory storage industry. Prior to disk storage, magnetic tape was the industry's primary information storage medium. Advancements in disk technology, though, quickly outpaced the speed and efficiency of tape systems—resulting in the obsolescence of tape for most applications.

Augmenting growth of both hard disk and floppy disk drives in the 1980s was the proliferation of the microcomputer. Throughout the 1980s these personal computers (PCs) relied solely on magnetic disk technology for memory storage. Sales of PCs skyrocketed from less than 500,000 per year in 1980 to 10 million in 1990; the demand for disk storage devices soared. Growth in workstations, microcomputers, and mainframes also spurred demand. By 1990 manufacturers were shipping more than 26 million Winchester hard drives and about 40 million floppy drives per year.

Despite the decline of market share attributable to magnetic tape drives, this segment experienced steady growth during the 1980s and early 1990s. By 1989 manufacturers were shipping about 1.6 million tape drives per year, most of which were being used to backup hard disks and network systems. Furthermore, tape drive sales were expected to grow at an annual rate of approximately 8 percent in the early 1990s.

As computer memory storage device manufacturers entered the 1990s, new storage technology was beginning to gain widespread attention by the industry and consumers. Optical memory, which had been viewed essentially as an experimental or specialty technology during the late 1980s, was beginning to establish itself in mainstream business and consumer markets. There was also an increasing interest in semiconductor memory.

The 1990s. Magnetic disk drives continued to dominate industry offerings in the 1990s. The number of hard drives sold, for instance, climbed steadily to 31 million in 1991 and to 37 million by 1992. Floppy drive sales volume also climbed, much as it had during the 1980s, to about 45 million per year by 1993. Despite a massive shakeout in the PC market, which was placing severe downward pressure on PC prices, many storage device producers enjoyed solid profit growth in the early 1990s. This was partly a result of PC industry price wars that were boosting PC unit shipments.

Still, disk drive prices continued to drop for all but the latest models. While the most advanced drives still provided comfortable profit margins, mainstream technology grew ever cheaper and less profitable. Between February and June of 1993, for example, disk drive prices dropped 25 percent.

To counter the shift toward commoditization, storage device makers in the mid-1990s tried to expand their development and production of technologically superior products that offered higher profit margins. Some firms focused on 2.5-inch and 1.8-inch hard drives for notebook computers to stimulate sales. Many of the weaker competitors were bought out.

By 1995 several companies had expanded the marketing and manufacturing of removable media, both tapes and disks, into the home computer market. Companies such as Iomega and SyQuest developed affordable tape drives and removable disks available for $150 to $200, with cartridges and disks costing between $20 and $25 each. These removable units could hold between 100 megabytes and 2 gigabytes of information to backup or enhance hard drive capacity.

Around the same time, CD-ROM drives became standard accessories on most new computers. CD-ROM drives were originally targeted at libraries and research organizations because CD-ROMs's capacity was so much greater than anything used in the consumer market. However, the popularity of games and multimedia software, along with the mushrooming size of general applications, made CD-ROMs a requisite feature, lest home users and corporate administrators be forced to juggle dozens of floppy disks in order to install a single program. The speed of CD-ROM drives rapidly increased, as the technology reached mainstream status. By the late 1990s, recordable CD drives and the newer Digital Versatile Disc (DVD) technology, geared toward reproducing full-length movies and holding other storage-intensive applications, were also increasingly common.

Although they accounted for only a small portion of industry sales, magneto-optical (MO) drives gained popularity in the mid- to late 1990s. These storage devices combined the ease and portability of a floppy disk with the capacity and speed of a hard disk. The systems use both magnetic and optical technology. The drive reads and writes the disk with a read/write head assisted with a pulse-modulated laser beam. In 1996 MO drives came in two sizes, 5.25-inch and 3.5-inch, and could store between 128 megabytes and 1.3 gigabytes of data.

Corporate storage and reliability needs fueled vigorous demand for redundant arrays of inexpensive disks (RAID), which were first introduced in 1987. RAID storage systems allow several hard drives to work in concert as a single, high capacity, relatively inexpensive, and dependable memory backup device. Applications include backup storage for mainframes, networks, and other high-end systems. Sales of RAID units skyrocketed from just 16,000 in 1991 to well over a million units by 1998. RAID product revenue also grew tenfold from 1992 to 1998, from $1.2 billion to more than $12 billion.

Flash memory cards, first developed in the early 1990s, were another growth vehicle for the industry by the mid- and late 1990s. The compact, energy-efficient, high-capacity devices proved to be weighty contenders in the bid to serve the rapidly expanding notebook and penbased computer markets.

During the late 1990s, hard drives—which cost an average of $11.54 a megabyte back in 1988—continued to fall in price while increasing in size. According to the 1999 Disk/Trend Report, the price per megabyte of hard disk space was expected to continue to tumble, falling from 4.3 cents in 1998 to a projected 0.3 cents in 2002.

Tape drive sales were mixed in the late 1990s, with sluggish performance from devices aimed at individual PCs but better results from drives aimed at servers. Newer tape automation systems have gained popularity because they can reduce the workload associated with managing tape backups. Tape drive manufacturers hoped to secure better footing in the network storage arena by offering higher-capacity formats, including the new Linear Tape Open (LTO) standard backed by three of the industry's biggest participants—Hewlett-Packard, IBM, and Seagate. A key selling point for tape technology was its low price compared to disk drives.

In the early 2000s, removable and optical storage was one of the industry's slowest segments as far as revenue growth. The main growth technologies were DVD-ROM drives and writable CD and DVD drives, whereas revenues from floppy drives and cartridge drives had stagnated.

Current Conditions

The computer storage industry still contends with the market paradox of unprecedented demand by computer users for storage capacity and versatility, yet unwillingness to pay commensurately more for storage devices. During the mid-1990s, most new hard drives had a capacity of 1 GB. However, by 2002 most PCs contained hard drives in the 20-60 GB range. According to PC World , maximum hard disk size increased from 27.2 GB in late 1999 to 250 GB in late 2002. Prices fell from $14.67 per GB to $1.20 per GB, respectively. As prices per GB fell, so did the size of hard disks. For example, in 2002 Toshiba manufactured a 20-GB disk drive that was less than 2 inches wide. The drive was used by Apple in its popular iPod music player.

In the early 2000s, hard disk drives continued to be the industry's strongest category. As of 2002 the industry was forecast to ship an estimated 217 million hard disk drives, according to Gartner Dataquest. By 2006 shipments were expected to reach 373 million, driven by annual increases of more than 10 percent. U.S. companies hold a dominant share of the world market. Driving growth in the hard disk categories were non-PC devices, especially digital video recorders, set-top boxes, digital audio recorder-players, video game systems like Microsoft's Xbox, personal digital assistants (PDAs), and different kinds of still and motion digital cameras. These devices were expected to significantly increase the demand for hard disk drives well into the 2000s.

The business market continues to provide solid demand for RAID systems. According to Insight , Gartner Dataquest forecast "a 73 percent combined annual growth rate in terabytes configured and delivered in storage systems to the RAID markets from 2002 to 2006." More network-oriented storage systems, like storage-area networks (SANs) and network-attached storage (NAS) devices, also remained popular in the early 2000s. SANs combine multiple disk arrays with controller hardware and software to create stand-alone and interdependent storage systems for large networks and heavy-traffic distributed environments. NASs, on the other hand, provide supplemental storage capacity to smaller networks without taxing existing servers.

In the early 2000s, tape was still a popular storage medium for many corporate information technology (IT) departments, many of which had made considerable investments in tape systems over the years. In late 2002 IBM, StorageTek, and Quantum joined with EMTEC, Fujifilm, Imation, Maxell, RSS, Seagate, and Sony to form a new industry association called the Tape Technology Council. According to the council, its main objective was "to provide unified promotional activities to increase the awareness of tape technology for data storage applications." This baffled some observers, since a number of these firms (including IBM, StorageTek, and Quantum) manufactured newer emerging technologies like Advanced Technology Attachment (ATA) hard drives that competed with tape devices in the corporate sector.

Industry Leaders

The storage industry consists of both integrated and independent manufacturers. Among the largest integrated players are IBM and Hewlett-Packard, which dominate certain product segments of the business, especially in technologies geared toward large companies.

Seagate Technologies Inc., of Scotts Valley, California, is among the largest independent producers of storage devices. In its fiscal year 2002, Seagate's revenues reached $6.8 billion. That year, according to the company, Seagate sold more hard drives (10.2 million) to the enterprise market than IBM, Fujitsu, and Maxtor combined, leading the market by more than 6 million drives. The company achieved its dominant position in part through acquisitions, the biggest of which was its 1999 purchase of Conner Peripherals, its closest competitor. Conner Peripherals had led the market in 3.5-inch hard drives. Seagate remains one of the most vertically integrated firms in the industry; it manufactures most of the parts that go into its drives. Texas Pacific Group and Silver Lake Partners led a group of investors that brought Seagate under private ownership in late 2000.

EMC Corp. of Hopkinton, Massachusetts, led the fast-growing market for high-end network storage subsystems in the early 2000s. The company has established itself as the premier provider of top-of-the-line storage systems, software, and services to major corporations. EMC faces strong competition from the likes of IBM, Hewlett-Packard, and Hitachi Data Systems. In 2001 the company recorded revenues of $7.1 billion.

Quantum Corp. of Milpitas, California, was another leading independent in the early 2000s. Like Seagate, Quantum has relied on strategic acquisitions to expand its business, including the takeover of the former Digital Equipment Corp.'s storage device business (the rest of DEC was later bought by Compaq). The company is a major vendor of tape drives, particularly those using the Digital Linear Tape (DLT) format—its primary focus in the early 2000s. The company reported $1.1 billion in revenues in its fiscal 2002, a decrease of almost 23 percent from the previous year.

Other industry leaders include California-based Maxtor, with 2001 sales of $3.8 billion; Western Digital Corp. of California, with $2.2 billion in fiscal 2002 revenues; Storage Technology Corp. of Colorado, with 2001 revenues of $2.0 billion; and California-based Iomega, which recorded sales of $834.0 million in 2001.

Workforce

The computer storage industry workforce includes a higher proportion of electrical and electronics engineers than most other U.S. industries. The industry also hires large numbers of trained precision assemblers, as well as a significant number of parts assemblers and fabricators.

During the early 2000s, employment levels for storage device manufacturers were falling along with many other segments of the computer industry. In 1997, 42,012 people were employed in the industry, including 20,428 production workers. By 2000 these numbers had fallen to 32,296 and 14,988, respectively.

The number of both precision and parts assemblers employed by manufacturers was expected to decline between 40 and 55 percent from 1990 to 2005. Automation, as well as outsourcing of labor tasks to foreign countries, will account for much of this loss. Clerical positions will also decline drastically, by about 30 percent. Even the demand for engineers will fall by 1 or 2 percent by 2005, as companies form corporate alliances that allow them to reduce overlapping research and development expenditures.

On the bright side, the demand for systems analysts and computer scientists is expected to increase by about 40 percent between 1990 and 2005. Furthermore, opportunities will become available to professionals who can help develop cutting edge technologies, particularly for optical and semiconductor products.

Research and Technology

Historically, industry research and development has resulted from both strategic alliances and government initiatives. For example, General Electric, AT&T, Honeywell, and IBM established the Optoelectronic Technology Consortium (OTC) in July 1992 to advance domestic optical technology. The OTC was scheduled to continue for 30 months and was backed by $8 million in initial funding. Half of the funding for the OTC was supplied by the federal Defense Advanced Research Projects Agency (DARPA).

In addition to the OTC, the Microelectronics and Computer Technology Corp. (MCC), also an industry consortium, began a five-year research project on holographic mass-storage subsystems. This effort was backed by $10.3 million in federal grants and $12.7 million from consortium members. A similar government/private enterprise effort was underway in California that involved the National Institute of Standards and Technology and several universities. Its purpose was to integrate optical technology into a prototype computer that might eventually lead to a desktop supercomputer.

The Future. Memory storage devices will continue to play a leading role in the advancement of computer technology, as they have since the birth of the computer industry. The role of the memory storage device industry will become increasingly blurred, however, as the computer, telecommunications, consumer electronics, information, and entertainment industries converge into a massive multimedia industry that interconnects various technologies and services. Multimedia, by its most basic definition, will combine data, audio, and video signals into one digital stream.

The dominant technologies that will drive this metamorphosis are data processing, storage, interface, fiber optics, wireless, compression, and digital broadband switching. As a result, companies from many industries will find themselves competing and cooperating with firms in completely separate industries. Firms that once delivered memory storage solely for the computer industry will be selling their technology to a wide range of markets. The advancement of flash memory technology provides evidence of this trend. Semiconductor and disk storage companies have cooperated to develop flash memory storage products not only for computers, but also for digital cameras, telephones, automobiles, and other devices.

Further Reading

"About IDC," 2003. Available from http://idc.com .

Buchok, James. "Why Trust an SSP?" Computing Canada, 30 November 2001.

Carbone, Rob. "The Lure of Enterprise Storage." Computer Reseller News, 18 March 2002.

Disk/Trend, Inc. 1999 Disk/Trend Report. Mountain View, CA, 1999. Available from http://www.disktrend.com .

"Hard Drive Industry Mantra: Bigger, Smaller, Cheaper, Faster." The Online Reporter, 28 October 2002.

"Hard Drive Sizes Climb, but Prices Don't." PC World, November 2002.

International Disk Drive Equipment and Materials Association. Welcome to IDEMA. Santa Clara, CA: 2000. Available from http://www.idema.org .

Monroe, John. "Alchemy and Rigorous Science: The Evolution of Hard Disk Drives." Insight, Fall 2002.

Moore, Fred. "Storage 2000." Computer Technology Review, December 1999.

Neil, Stephanie. "Storage Cellars." PC Week, 26 July 1999.

O'Regan, Rob. "In Enterprise Storage Arena, EMC Sets the Standard." PC Week, 26 July 1999.

Ress, William. "The Emerging Non-PC Storage Market: Where and When?" Insight, May/June 2001. Available from http://www.idema.org .

Rigney, Steve. "Better Ways to Serve and Protect." PC Magazine, 25 May 1999.

"Tape Backup Gets Some Surprising Support." eWeek, 12 November 2002.

Tape Technology Council. "About the Council." 5 January 2003. Available from http://www.tapecouncil.org .

Titch, Steven. "So You Want to Be an SSP: Storage is Poised to Be a Hot Growth Area." America's Network, 1 March 2001.

"Top 10 Hard Drives." PC World, November 2002.

U.S. Census Bureau. Annual Survey of Manufactures. Washington, D.C.: U.S. Department of Commerce, Economics and Statistics Administration, U.S. Census Bureau, February 2002. Available from http://www.census.gov .

——. "Computers and Office and Accounting Machines:2001.". Current Industrial Reports. Washington, D.C.: U.S. Department of Commerce, Economics and Statistics Administration, U.S. Census Bureau. September 2002. Available from http://www.census.gov .



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