Larry Cabrinety,
Vice President,
Video, Image and Print Systems Group

For the millions of people worldwide who use Digital's computer equipment, the computer is not the sophisticated system in the back room, or the complex network. It is the equipment they use each day-the terminal or monitor, keyboard and mouse, desktop printer or network printer system.

Today's users demand products with high levels of usability and superior ergonomic features. Digital's products set worldwide standards for the user interface to computer systems. In the 90s our focus is to offer products that operate in multivendor environments with the goal of delivering a complete computing solution. In this issue you will read about some of the Video, Image and Print Systems (VIPS) group's products and technologies that support network computing and standards-based environments.

Digital entered the video terminal market in 1975 with the VT52 for its time-sharing users. Its replacement, the VT100, embodied two important principles-the use of standards in data communi- cations interchange and the protection of customer investments through backward compatibility of new generations of products. The VT220, introduced in 1983, and the cost-effective VT320 ter- minals saw the addition of functionality and ergonomic features which established Digital as a leader in the commodities market.

In March 1990, Digital entered the X terminal market with the introduction of the VT1000, followed by the VT1200 and VT1300 terminals later that year. The emergence of MIT's X Window Systems as the accepted industry standard for windowing sys- tems provided a standards-based environment for distributed applications display processing. The X terminal user can now benefit from the graphical user interface, sophisticated appli- cations, and standards of performance previously available only on workstations. X terminals run X11 server code which is oper- ating system independent and ideally suited for heterogeneous, network-based computing environments. In this issue you will read about the engineering decisions made as the X terminals were developed.

There is a growing need in the industry to have imaging appli- cations run alongside conventional text and graphics applica- tions. Technical documentation is an example of this. Imaging applications, however, have special requirements to achieve ac- ceptable end-user performance. Although the X11 software can handle images as bit-map data, software and hardware assistance is required to achieve acceptable performance. Digital has de- signed DECimage hardware accelerators for rapid processing of image data. This technology is included in the DECimage 1200 and will be incorporated in following generations of X termi- nals. To make this possible, Digital developed extensions to the X server software that support the high-speed transport and display of image data. To assure open standards, the extensions have been proposed to MIT for incorporation into releases of the X11 server software.

In November 1990, Digital announced its next generation of X terminals. The VXT2000 terminal provides virtual memory and supports both a traditional host-based model with software downloaded to the terminals as well as the server style of X terminal computing.

The VXT2000 terminal was designed to support TCP/IP and LAT protocols, and further demonstrates our commitment to openness and support for customers' multivendor environments. This same philosophy is seen in our printer products and our open desktop bus.

Digital pioneered the distributed printing business with net- worked laser printers. This product area began when we combined two concepts which had not been combined before- mid-range laser printers and networks. In the mid-1980s most large-scale comput- ing was done on mainframe computers with large printers attached

directly to these systems. Typically these dedicated print- ers were only accessible to users on that particular system. Digital's distributed computing provided an alternative to the mainframe. By combining the power of multiple systems in clusters or on networks, a new distributed large system was cre- ated. A printing solution was needed to effectively work in this new distributed computing environment. The PrintServer series addressed this need.

PrintServer products enabled printing resources to be directly connected to networks for the first time, and since they were on the network and not tied to any one system, they were ac- cessible by all systems on those networks. They enabled the complex printer functionality previously found only in dedi- cated mainframe printers to be distributed throughout end-user environments.

As these mid-range printers migrated out of the computer room and into the office, new demands for functionality were created. Large groups of users brought many different requirements for printing, and our goal was to satisfy as many as possible in a single PrintServer. For example, some people need "A" size paper for office correspondence, while others may need "B" size paper for CAD/CAM or accounting work, and still others need transparencies for presentations. The PrintServer is flexible enough to have all of these different types of media available and offer both simplex and duplex printing.

In 1985 when Digital was first developing the PrintServer, there was no industry standard way of describing the contents of a page to a printer. Each major vendor had its proprietary lan- guage, and none offered the compatibility necessary to achieve our print system vision. Our goal was to create a family of products, from large to small, that offered compatibility for all applications. To achieve this goal we had to select a pro- tocol that would enable us to print any file on any printer. At that time Adobe Systems, the developer of PostScript, was a small start-up company in Silicon Valley. PostScript was not a standard, and in fact, only a single PostScript laser

printer model had been shipped, the original Apple LaserWriter. Our technical community felt PostScript was the best solution to our needs, and at that point Digital committed to adopt- ing PostScript as our strategic page description language. PostScript printers and PostScript application support are now pervasive throughout the industry and standard printing protocols enable interactive communication with hosts on the network.

Significant advances have taken place in the PrintServer se- ries over the past seven years. An entire MicroVAX II system was housed within the original PrintServer 40, along with custom hardware acceleration boards developed by the Hardcopy Group to enable printing at 40 pages per minute. In this issue you will read about the single-board controller that replaces the MicroVAX II and offers far more processing power. Using the lat- est system-on-a-chip technology, our new turbo board provides leadership performance for our printers. The CCITT image decom- pression chip enables us to provide full-speed image printing to our customers as the image market develops.

The first PrintServer systems supported printing from VMS hosts over DECnet networks. Since then the breadth of platform sup- port has increased to include first ULTRIX systems and then UNIX operating systems. A software kit for Sun systems will be available soon. In expanding PrintServer connectivity to include UNIX systems and TCP/IP networks, we again faced the problem that no network printing protocol existed for TCP/IP. With the help of Digital's experts at the Western Research Laboratory, we were able to develop a solution. In this issue, we discuss the creation of a network printer access protocol for TCP/IP. Today this network protocol is a proposed standard at the In- ternet Engineering Task Force, the body controlling the TCP/IP protocol.

The development of the ACCESS.bus product has brought an easy, standard way to link a desktop computer to many interactive user interfaces. This open desktop bus is currently implemented on the Personal DECstation 5000 workstation, and implementations on future RISC workstations and video terminals is underway. Developers of Digital's products will continue to place a high priority on open standards. The papers included in this issue of the Digital Technical Journal will provide insight into the key areas of technology used in the design and development of VIPS products.