Zenith Data Systems Corporation (ZDS) was an American computer systems manufacturing company active from 1979 to 1996. It was originally a division of the Zenith Radio Company (later Zenith Electronics), after they had purchased the Heath Company and, by extension, their Heathkit line of electronic kits and kit microcomputers, from Schlumberger in October 1979. ZDS originally operated from Heath's own headquarters in St. Joseph, Michigan. By the time Zenith acquired Heathkit, their H8 kit computer already had an installed fanbase of scientific engineers and computing enthusiasts. ZDS' first offerings were merely preassembled versions of existing Heathkit computers, but within a few years, the company began selling bespoke systems, including the Z-100, which was a hybrid 8085- and 8088-based computer capable of running both CP/M and MS-DOS.

ZDS largely avoided the retail consumer market, instead focusing on selling directly to businesses, educational institutions, and government agencies. By the late 1980s, the company had won several lucrative government contracts worth several hundreds of millions of dollars combined, including a US$242-million contract with the United States Department of Defense—the largest such computer-related government contract up to that date. In 1986, the company made headlines when it beat out IBM for a contract with the Internal Revenue Service to supply a portable computer. ZDS' SupersPort laptop was released in 1988 to high demand, and it soon cornered roughly a quarter of the entire American laptop market that year. The company reached a peak in terms of revenue in 1988, generating US$1.4 billion that year. The following year saw ZDS floundering in multiple ways, including a cancelled contract with the Navy and a botched bid to increase its consumer desktop sales. In late 1989, ZDS was purchased by Groupe Bull of France for between $511 million and $635 million.

Following the acquisition, ZDS moved from Michigan to Buffalo Grove, Illinois. In 1991, Enrico Pesatori took over ZDS and attempted to repair their relations with dealers while diversifying their product lineup and modes of sales. ZDS made a slow recovery into the early 1990s, helped along by a lucrative contract with the Pentagon in 1993. Pesatori was replaced that year with Jacques Noels of Nokia, who further diversified the company's lineup. ZDS' revenue steadily grew in both their North American and European markets in the beginning of 1994. The company was acquired by Packard Bell in February 1996, in a three-way deal which saw Groupe Bull and Japanese electronics conglomerate NEC increasing their existing stakes in Packard Bell. Later, NEC announced that they would acquire Packard Bell, merging it with NEC's global personal computer operations. ZDS continued as a brand of computer systems under the resulting merger, Packard Bell NEC, from 1996 until 1999, when Packard Bell NEC announced that they would withdraw from the American computer market.

Zenith Data Systems Corporation (ZDS) was founded in October 1979 following the US$64.5-million acquisition of the Heath Company from Schlumberger Limited by the Zenith Radio Company. The company's initial headquarters were located in Heath's own headquarters in St. Joseph, Michigan. Edward J. Roberts, who joined the Zenith Radio Company in 1971, was named ZDS' first president. Heath was a manufacturer of microcomputers and do-it-yourself electronics kits, the latter sold under the Heathkit brand; meanwhile, Zenith Radio Company (later Zenith Electronics) had been long a market leader in the American electronics industry, particularly with radios and television sets.

ZDS' first computers were preassembled versions of Heathkit computers. As subsidiary of a television company, ZDS could obtain monitors at cost. Heath had a loyal fanbase comprising computing enthusiasts and scientific engineers by the time Zenith acquired the company in 1979. The first Heathkit computer, the H8, was released in 1977 and sold in kit form. It was built on Intel's 8080 processor and ran software on audiotape and punched tape (with the H10 puncher–reader). The H8's operating system, HDOS (Heath Disk Operating System), could only read hard-sectored 5.25-inch floppy diskettes. In around 1980, ZDS began selling systems sold with the hybrid Heath/Zenith branding; the CP/M operating system was adapted to the entirety of ZDS' computers under this branding scheme by 1981. The early Heath/Zenith computers (the H88, H89 and Z-89) were based on the Z80 processors and ran either HDOS or CP/M operating systems.

Long after products bearing only the Zenith name had accounted for the majority of the company's sales, ZDS continued selling their computers in kit form under the Heathkit or Heath name—the equivalent of the ZDS Z-150 IBM PC compatible was the Heathkit H-150, for example. The company opened more Heathkit Electronic Centers while also selling through Zenith dealers and seeking corporate customers. The company also continued Heath's practice of publishing unusually clear product documentation, distributing schematics, and selling the source code to HDOS and other software in printed form.

ZDS introduced the Z-100, its first computer not based on a kit design and second 16-bit product after the H11 minicomputer, in 1982. Targeted at business professionals, it had both the Intel 8085 and 8088 microprocessors; five S-100 bus slots for expansion; and an integrated high-resolution graphics chip with color capability. For operating systems, it could boot into either Digital Research's CP/M-85 or Z-DOS, a modified OEM version of MS-DOS licensed from MS-DOS that possessed the latter's filesystem but which was not fully compatible on the API level with MS-DOS, leading to compatibility issues with certain applications. While lacking in the PC-compatibility department, the Z-100 proved popular as a bridge machine for CP/M developers who wanted to get a head start on DOS and x86 programming. Later machines in this Z-prefixed line (such as the Z-150 series, the Z-200 series, the Z-300 series, and the Z-400 series) were fully compatible with the IBM PC. The AT-based Z-200 in particular, while not touting many technical improvements over IBM's PC AT, was nonetheless praised for its sturdy construction.

ZDS avoided the retail consumer market, instead focusing on business and government customers, such as companies, universities, and government agencies. Government contracts were of paramount importance for ZDS, representing the bulk of the company's sales efforts. John Frank, ZDS' vice president of marketing, explained: "We'd like to have [retailers], but we don't need them". ZDS' president Donald Moffett in 1982 further stated: "We have no expectations of being first or second in the desktop market". Regardless, in fiscal year 1984, ZDS sold 16 percent of the 37,000 computers that the United States government purchased, second to IBM's 27 percent. After a failed bid to sell their computer systems at college bookstores, ZDS found success in marketing to fraternities and sororities directly in 1985. By that year, ZDS was overall the second-largest PC-compatible company, after Compaq. ZDS' CEO that year, Robert Dilworth, attributed its success to recognizing, unlike other computer companies, that the PC compatible was a commodity with falling prices like televisions: "Basically, we move boxes". ZDS' 1985 revenue grew to $352 million, and in March 1986 The New York Times called the division's success one of Zenith Electronics' "proudest accomplishments", amid the parent company's losses in the television market against Japanese competition.

In October 1983, the United States Navy and Air Force awarded a $27-million computer contract to ZDS. In 1984 ZDS won a $100-million contract with the United States military for "eavesdrop-proof" computers compliant with the Tempest standard. In 1986 it won two other large contracts, one for portable computers for the Internal Revenue Service (IRS), and a $242 million contract—the largest computer contract the U.S. federal government had awarded up to that point—for 90,000 computers to the United States Department of Defense.

ZDS introduced a number of innovations in the personal computer industry throughout the 1980s. One unique feature of most ZDS' PC-compatible systems was the key combination Ctrl+Alt+Ins, which would interrupt the running program and break into a machine-language monitor. This monitor program originated with the Heathkit H8 computer; PAM-8 (Panel Monitor-8), included in ROM, allowed the user to trace or resume program execution, change machine settings, run diagnostic routines, and boot from a specific device.

ZDS' ZP-150 laptop, released in 1984, was an early entry in the first wave of laptops of the early 1980s. ZDS followed up the Z-150 with the heavier, less-elegant Z-138 portable computer in 1985. They quickly followed this up with the Z-160 portable, which featured pop-up 5.25-inch disk drives. Also in 1985, the company introduced the Z-148, one of the most inexpensive IBM PC-compatibles on the market at the time, with a suggested retail price of $2,200 (with typical resellers discounts lowering this figure substantially, according to InfoWorld). The Z-148 was kept inexpensive by its small footprint; one sacrifice was the lack of any ISA expansion slots. The company's Z-171 portable was built into a lunchbox form factor. This computer was originally developed by Morrow Designs and sold as the Morrow Pivot II in May 1985. ZDS acquired the rights to co-manufacture the Pivot II rebadged as the Z-171 and unveiled the latter in November 1985. ZDS shocked industry observers in early 1986 when it was awarded a contract to sell 20,000 Z-171s worth $27 million to the IRS, beating out IBM and their PC Convertible.

In 1987, Microsoft chose ZDS to be the first pack-in distributor of its variant of OS/2 1.0, co-developed with IBM; that same year, Microsoft developed a character-based windowing file manager for ZDS' all-in-one Eazy PC called MS-DOS Manager, a precursor to Microsoft's later DOS Shell. In 1988, the company released the SupersPort line of laptops and the TurbosPort 386 portable computer, the latter being one of the first computers to have a "paper-white" monochrome LCD, owing to the use of a special STN display technology and a cold-cathode backlight. The SupersPort was very successful for ZDS, with the company reportedly selling over 173,000 units, cornering between 23 and 25 percent of the entire laptop market at the time. Contracts to sell fleets of computers to the United States Air Force and the IRS further increased ZDS' status as a leading computer manufacturer. By 1988's end, the company grossed $1.4 billion in revenues. ZDS' success allowed them to sponsor the Full Members' Cup, a football competition in the United Kingdom, starting in 1989 until the latter's discontinuation in 1992.

Despite having what Byte described in 1989 as "an excellent reputation for making quality hardware" with good customer support, that year first-quarter revenue fell roughly 41 percent compared to the previous year, dropping to $1.7 million. Its MinisPort subnotebook, which made use of a special 2-inch floppy disk format as the primary means of transferring data to and from the machine, sold more slowly than anticipated. Further, Unisys beat out ZDS in a $700-million bid to supply the military with desktop computer systems. The company soon after had a $534-million computer upgrade contract for the Navy cancelled by the General Services Administration. A ploy to boost sales of its desktop computers by requiring its laptop dealers to also sell their desktop models backfired, with an estimated 1,000 dealers across the United States pulling all ZDS products from their inventory in protest of this policy. After being dealt this blow, Zenith Electronics cut spending to ZDS' research and development operations in preparation for selling the subsidiary to the highest bidder. This had the effect of eliminating new product releases, causing sales to free fall as its existing offerings soon became obsolete. An interested buyer was found at the very end of the decade; in November 1989, Groupe Bull announced that they would acquire ZDS from Zenith Electronics for between $511 million and $635 million. The deal was finalized in December 1989.

ZDS' workforce peaked in number in 1990 with 3,800 workers, 1,800 of which were from their St. Joseph, Michigan, headquarters. Under new ownership, the company relocated from Michigan to Buffalo Grove, Illinois, after leasing 140,000 square feet (13,000 m) of office space at a newly built 12-story office building at Lake-Cook Road and Milwaukee Avenue. ZDS retained their old St. Joseph headquarters, refactoring it into a full-on engineering facility and manufacturing plant for the company's desktop computers.

After shuffling its executive team in 1990, Enrico Pesatori was named the first permanent CEO of ZDS under Bull's ownership in January 1991. Tasked with correcting course and rehabilitating ZDS' public image, Pesatori spearheaded the creation of a new lineup of laptops and put an end to the requirement that dealers stock desktops as well as laptops. Pesatori's new team meanwhile increased the company's advertising budget by half and launched a new advertising campaign targeting business users. ZDS also continued to expand their distribution channels and renewed their relationship with ComputerLand. As a result, sales started to improve. The company increased their shipments from 194,000 units in 1990 to 228,000 units (down from 445,000 units in 1988). The company also increased their investments in research and development, with expenditures in 1991 being 25 percent higher than the previous year, this trend following apace for 1992. By the middle of 1992, ZDS had additional manufacturing plants in Santa Clara, California; Billerica, Massachusetts; and Villeneuve-d'Ascq, France.

ZDS remained the largest supplier of computers to the federal government into 1991. In November that year, they and several other large computer companies, including Apple, lost a bid to supply the Department of Defense with 300,000 desktop computers, the winning bid valuated at $1 billion split between rival manufacturer CompuAdd Corporation of Austin, Texas, and systems integrator Sysorex Information Systems of Falls Church, Virginia. ZDS however won a bid to supply the Pentagon with 300,000 desktops worth $740 million in September 1992, this time beating out CompuAdd and Sysorex. Although ZDS' bid was temporarily voided after the latter two companies raised suspicions that ZDS was financially unstable, ZDS won back the contract in May 1993 on judicial appeal.

In 1992, ZDS launched a revamp of their desktop PCs, laptops, and monitors. The redesign extended to their products' case designs, featuring sleek lines meant to instill a sense of modernity. These efforts culminated in the release of the Z-Series laptops in June 1992. The Z-Series were touted as the lightest laptops available at the time, with built-in networking capability and color LCDs. The Z-Lite, the company's second attempt at a subnotebook, was co-designed by Frog of Germany, featuring an 8.5-inch LCD while weighing only 3.9 pounds (1.8 kg). ZDS themselves were commissioned to design and manufacture another company's product, the ThinkPad 300—IBM's second entry in their ThinkPad line of notebook computers.

The total sales for 1992 were estimated at $900 million—55 percent of which represented sales in Europe, and 40 percent of which represented sales from notebook models. While the company's overall sales slowly recovered, ZDS' retail market share continued to slide, decreasing from 3.4 percent in July 1991 to only 1 percent in July 1992. The company's officials cited a change in consumer purchasing behavior favoring superstore outlets (a sales channel in which ZDS had only a limited presence) as a reason for this decline. In an attempt to boost sales into 1993, ZDS restructured its field sales force and began focusing on direct sales to corporate accounts. In August 1992, after having poached CompuAdd executive Jerry Baldwin, ZDS launched the Z-Direct mail order catalog, mailing one million copies of its inaugural issue that year. The catalog offered desktop, server, and notebook products via a toll-free phone number. The catalog also included peripheral equipment from other manufacturers and software products from Microsoft, Novell, and Lotus Development. The company hoped that the direct sales approach would increase brand recognition and reach customers who were not targeted by other marketing channels.

Jacques Noels, formerly the head of Nokia Consumer Electronics, replaced Pesatori as CEO in January 1993. Pesatori meanwhile left to helm Digital Equipment Corporation's PC-compatible systems division. Under Noels' leadership, ZDS launched several new products, including the Z-Lite 425L, an upgraded version of their subnotebook featuring an i486SL processor clocked at 25 MHz; the Z-Notepad, a pen-enabled version of their Z-Note laptop; and the Z-Star V33VL series, a 486-based notebook PC line comprising three models, all featuring Cyrix's energy-conservant Cx486SLC microprocessor clocked at 33 MHz. ZDS also launched a new series of desktop PCs, the Z-Select 100 line, which came pre-installed with networking software compatible with Novell NetWare, Banyan VINES, and Microsoft LAN Manager. The Z-Select 100 was powered by a 25-MHz i486SX processor and featured 4 MB of RAM and a 170-MB hard drive. ZDS touted the power-saving capabilities of the Z-Select 100, including its idle power consumption of 60 watts and advanced power management capabilities, including user-definable time intervals on which the computer halts the processor to conserve power.

In 1993, Groupe Bull purchased a 19.9 percent stake in Packard Bell, then the fourth-largest PC seller in the United States (behind Apple, IBM, and Compaq), representing an undisclosed price. While Packard Bell had an overall market share in the United States of 37 percent, only five percent of this figure represented notebook sales—much lower than the industry average of roughly 20 percent. As part of the acquisition, ZDS agreed to provide Packard Bell with rebadged versions of its notebook and subnotebook PCs, eventually manufacturing for them the Packard Bell Statesman, released in October 1993. The two companies also agreed to collaborate on the design and production of future desktop PCs. ZDS reported a 30 percent increase in worldwide revenues by 1993's end, with North American revenues up 53 percent and European revenues up 22 percent. The number of units shipped also increased, with a rise of 89 percent in the US and 62 percent worldwide. ZDS by this point counted seven major distributors on its roster and had sales networks in over 30 countries.

In 1994, ZDS unveiled the Z-Stor line of wide area network products. The flagship product in the lineup was the Z-Stor Personal Server, a file server co-developed by the Desktop Workgroup Computing Initiative, a joint venture between ZDS and Novell. ZDS in 1994 also introduced the Z-Station 500, a desktop workstation, and the Z-Noteflex, a new line of notebooks. The Z-Station 500 touted improved power management, higher-specification graphics cards (implementing ATI's PCI-based Mach 32 card), and increased system performance. The Z-Noteflex meanwhile was designed to be modular, allowing users to swap the top housing of the laptop to switch between different display technologies (passive-matrix monochrome, passive-matrix color, and active-matrix, TFT color) and remove hard disk drives toollessly. The Z-Noteflex also possessed an internal VESA local bus, allowing expansion cards based on this architecture to be installed into the computer with the optional Flexshow docking station.

ZDS saw considerable growth in revenue in both their North American and European markets in the beginning of 1994. Comparing year-to-year first quarter profits between 1993 and 1994, there was an increase of 132 percent in North America and an increase of 42 percent in Europe. ZDS' annual sales revenues of roughly $1 billion made up around 40 percent of their Groupe Bull's total hardware revenues, according to a statement issued by the company. Furthermore, ZDS revenues were equally divided between North American and European markets, as well as between desktop and notebook products.

In February 1996, Packard Bell acquired Zenith Data Systems from Groupe Bull, in a three-way deal which saw Groupe Bull and Japanese electronics conglomerate NEC increasing their existing stakes in Packard Bell. As a consequence of the merger, 570 jobs were eliminated from ZDS' plant in St. Joseph. Shortly after, in June 1996, NEC announced that they would acquire Packard Bell, merging it with NEC's global personal computer operations. The merger was finalized in July 1996; the resulting division became known as Packard Bell NEC, selling computer systems under both NEC and Packard Bell faceplates. Select ZDS employees moved to Packard Bell NEC's headquarters in Sacramento, California, and ZDS lived on as a brand for certain systems manufactured by Packard Bell NEC and marketed in the United States between 1996 and 1999. For a brief period, Packard Bell NEC was the largest PC manufacturer, in terms of units shipped, in the United States, with 15 percent of market share; it was also the third largest PC vendor in the world in terms of sales at the end of 1996. However, Packard Bell NEC's market share would soon slide, and the company between 1997 and 1998 posted losses totaling more than $1 billion. In 1999, NEC withdrew Packard Bell NEC from the American market, while keeping it in Europe. Acer Inc. of Taiwan eventually acquired Packard Bell in 2008.

• Official website at the Wayback Machine (archived January 29, 1997)