INTRODUCTING APOLLO DOMAIN Imagine a very large computer system with large main memory and disk storage, high-performance graphics terminals, and a high-speed internal bus connecting the components. Suppose this internal bus could be lengthened dramatically without sacrificing performance. Then suppose that the rest of the large computer system could be divided into dozens of smaller computers, each retaining all the essential characteristics of the original. Finally, suppose all these smaller computers could plug into that extended bus. In essence, we've just described APOLLO Computer's DOMAIN system. A DOMAIN system is an integrated computer environment, con- sisting of from as few as one to as many as several hundred nodes, tied together by a high-speed, baseband communications network. Each node is a powerful, 32-bit computer, with up to 3.5 megabytes of main memory, sophisticated multi-window graphics capabilities, its own optional disk and peripherals, and the ability to support multiple concurrent processes, with each process having a virtual address space of up to 16 megabytes. In addition, each node has free access to data and programs stored at any other node, just as if these data and programs were local. Today, DOMAIN systems are at work in a wide range of appli- cation/market areas. These include: o interactive computer-aided engineering and computer-aided design applications in the fields of electrical, mechanical, architectural, engineering and construction, and mapping, o solving large-scale engineering/scientific problems in areas such as structural and finite element analysis, o computer science, including research, language development, and the teaching of computer science, o computer-aided software engineering, aimed at increasing programming productivity through the development of a powerful "programmer's work- bench" capability, o publishing, making use of DOMAIN's text pro- cessing, font generation, and graphics capabilities, o interactive financial modeling, simulation, and statistical analysis, utilizing DOMAIN's ability to run large-scale programs and manipulate large databases, o computer-aided manufacturing. In all of these areas, APOLLO is in the business of supplying sophisticated, high-performance, personal, network-based computer systems for enhancing the productivity of technical professionals. DOMAIN systems offer an extraordinary range of capabilities, including, o power to run mainframe scale FORTRAN programs, o high resolution graphics, closely-integrated for maximum performance, o a high-speed local area network architecture, providing economical resource sharing, low entry cost, and incremental growth, o a compatible growth path, providing long-term protection for users investments in application software and peripheral hardware as the DOMAIN technology advances, o high system availability and ease of maintenance. With these unique capabilities, DOMAIN makes possible an entirely new concept: a flexible, integrated computing environment in which mainframe power is readily available at each user's desk. MAINFRAME POWER THE APOLLO DOMAIN SYSTEM DELIVERS POWER AND PERFORMANCE THAT HAVE PREVIOUSLY BEEN AVAILABLE ONLY ON LARGE-SCALE, BATCH- ORIENTED MAINFRAMES OR TIMESHARING NETWORKS. AN IMPORTANT DEVELOPMENT IN THE EVOLUTION OF HIGH PERFORMANCE COMPUTER SYSTEM In the 1970's, timesharing and dedicated minicomputers emerged as alternatives to the centralized batch-processing mainframe computer. Now, in the 1980's, the DOMAIN system incorporates the strengths of both, with none of their disadvantages. Like timesharing, DOMAIN offers the economy of shared resources and the power of big-computer architecture, plus an unpre- cedented level of communication among users. At the same time, each DOMAIN user has his own dedicated computer, just as he would if he had his own minicomputer. Unlike a dedi- cated minicomputer, however, a single DOMAIN node has the resources - including virtual memory, large-scale shared disk storage, and high resolution graphics - to handle even very demanding engineering and scientific applications which would otherwise require a mainframe. Yet a single DOMAIN node costs a small fraction of the price of a large mainframe. And several hundred DOMAIN nodes can be integrated to create a single powerful computing environment. BIG COMPUTER POWER IN EACH DOMAIN NODE Every DOMAIN user has at his command a dedicated computer whose functionality is comparable to that of a traditional mainframe. Each DOMAIN node includes a state-of-the-art, 32-bit processor; from .5 to 3.5 megabytes of main memory, implemented with advanced 64 kilobit RAM technology, with error checking and correction (ECC) as a standard feature; optional dedicated high-speed disk drives, line printers, and other peripherals; and a network-wide virtual memory operating system (AEGIS) supporting up to 15 concurrent pro- cesses per node, each process able to address up to 16 mega- bytes of virtual memory. This allows DOMAIN users to take on a wide range of demanding computation-oriented applications, in areas such as computer-aided engineering, CAD/CAM, and scientific analysis, publishing, modeling, and financial analysis. PERFORMANCE ENHANCEMENT MODULE DOMAIN computing power is extended by the performance enhance- ment module. The module is a hardware option containing both a cache memory and a floating point processor on a single printed circuit board. The 4-kilobyte cache memory reduces effective memory cycle time, so the processor spends less time waiting for instructions and data fetches. The floating point processor portion of the performance enhancement module provides single precision (32 bits) and double precision (64 bits) floating point arithmetic functions, plus several special-purpose instructions, including register-state save and restore, and a polynomial evaluation primitive. HIGH RESOLUTION GRAPHICS THE DOMAIN SYSTEM OFFERS MORE ADVANCED, CLOSELY-INTEGRATED GRAPHICS CAPABILITIES THAN ANY OTHER COMPUTER SYSTEM EVEN APPROACHING ITS PRICE. THESE CAPABILITIES INCLUDE MONO- CHROMATIC OR COLOR BIT-MAPPED DISPLAYS; DISPLAY MANAGEMENT SOFTWARE THAT ALLOWS THE USER TO PRESENT A PRACTICALLY UN- LIMITED NUMBER OF VIEWS ON THE SCREEN SIMULTANEOUSLY, AND TO MOVE AMONG THEM AS FREELY AS IF THEY WERE PIECES OF PAPER ON A DESK; AND A GRAPHICS TOUCH PAD THAT PUTS CONTROL OF THE DISPLAY SCREEN LITERALLY AT THE USER'S FINGERTIPS. BIT-MAPPED DISPLAY Each of the DOMAIN bit-mapped, raster-scan displays incor- porates an independent RAM memory: 128 kilobytes for the monochromatic displays and one megabyte or optional two mega- bytes for the color display. The contents of RAM memory are directly mapped onto a high-resolution screen for detailed presentation of both character fonts and graphic images. Each point on the screen is represented individually in RAM memory. The screen is constantly refreshed, and changes in the bit-map memory are instantaneously displayed on the dis- play screen. A complete new screen can be constructed in as little as a fraction of a second. This bit-map memory is directly addressable by the CPU, allowing programs to easily modify its contents. However, the display controller is a separate device on the node's internal bus, so the display can be refreshed without interference while the CPU is running. MULTIPLE-WINDOW DISPLAY The bit-mapped display supports multiple windows, which can be presented side by side or overlaid in whole or in part. The display manager allows any window to be brought into full screen view instantly. This windowing capability allows the operating system to support multiple command environments simultaneously. Separate windows provide "virtual terminals" connected to multiple programs and data. Because there is no need to wait for one program's completion before starting to work with another, it is possible to move from one window - and one program context - to another with complete freedom. This new module of concurrent interaction saves precious time in the software development and debugging cycle. DISPLAY HARDWARE Two monochromatic DOMAIN display screens are available: a 19-inch, horizontally oriented (landscape) display, and a 15-inch, vertically-oriented (portrait) display. Each dis- play has a visible field of 800 x 1024 pixels. For user comfort, each screen has a brightness control, and produces either a black-on-white or a white-on-black, reverse image display. The displays are free standing units; they can be set up as far as 3 meters from the main DOMAIN node cabinet, so system users have considerable freedom in setting up work areas for their own efficiency. The third DOMAIN display at a 19-inch, highly interactive, square-format color monitor that incorporates all of the features of the monochromatic displays, plus a long list of others, including: high resolution 1024 x 1024 pixel display, with each pixel 4 or 8 bits deep (supporting 16 or 256 colors), up to 2MB or dedicated display memory; hardware raster ops; hardware pan and zoom; area fills, high-performance vector generation; and a 20 megabits/sec/plane high speed memory to memory transfer (bit BLT) capability. All of the DOMAIN displays include a keyboard with 28 user- programmable keys. Eight of these are special function keys that can be defined by the user for each virtual terminal. A HIGH-PERFORMANCE NETWORK THE DOMAIN SYSTEM INCORPORATES A DEMAND-PAGING NETWORK THAT ALLOWS ALL NETWORK USERS TO SHARE SYSTEM RESOURCES - DATA, PERIPHERALS, AND SOFTWARE - AUTOMATICALLY, AT DISK SPEEDS, WHILE RUNNING THEIR PROGRAMS, LARGE OR SMALL, CONCURRENTLY AND INDEDENDENTLY. A DIFFERENT SORT OF NETWORK In the traditional sense, the DOMAIN system isn't really a "network" at all. The term "network" usually implies a system or scattered computers and terminals, tied together by low-performance communications lines. Because moving infor- mation across them is clumsy, slow, and expensive, traditional networks are preoccupied with layers of communications pro- tocols. In contrast, each DOMAIN node has direct access to data and devices anywhere in the system, just as if they were local. And communication is at 12 megabits per second, the speed you'd expect for internal operations. The DOMAIN network is a token-passing, base-band, high-speed local bus. The network is a highly flexible communication channel, over which text, graphic images, engineering documents, reference materials, letters, and memos, along with directories, can be made available instantly to the entire user community. DEMAND-PAGING NETWORK DOMAIN is the first computer system to extend the concept of demand-paging, common to many virtual memory computers, across an entire multi-user network. Under the DOMAIN demand paging-concept, when a user requests access to a file on either a local or a remote disk, the disk immediately passes to the main memory of the user's node a 1024-byte "page" containing the requested data. Additional data is sent, page-by-page, on demand. This demand-paging concept is both fast and efficient. Only the data that is requested is sent, so there are no long delays while an entire file is sent; processing can start immediately. At the same time, data is sent in sufficiently large blocks that the number of data transfers is relatively low. And, of course, each page of data is transmitted at very high speed (12 million bits per second), so throughput is high and response is very rapid. At the same time, because data is sent a page at a time, no single user tie up the network for long periods with bulk transmissions. FAST, DEPENDABLE SYSTEM RESPONSE Predictable response is a critical factor in user satisfaction and productivity. In timesharing systems, users find them- selves frustrated by delays whenever the central computer is heavily loaded. And a dedicated minicomputer can be brought to a standstill by even a relatively small peak in computing demand. In the DOMAIN system, each time a new user is added, another node - itself a dedicated computer system - is also added. Therefore, instead of diluting computer power, the addition of users actually expands total system capability, and response remains fast, consistent, and predictable.