Английская Википедия:Apollo/Domain
Шаблон:Short description Шаблон:More footnotes Apollo/Domain is a series of workstations that were developed and produced by Apollo Computer from Шаблон:Circa to 1989. The machines were built around the Motorola 68k series of processors, except for the DN10000, which has from one to four of Apollo's RISC processors, named PRISM.
Operating system
The original operating system is Apollo's own product called Aegis, which was later renamed to Domain/OS. The Aegis and Domain/OS system offers advanced features for the time, for example an object oriented filesystem, network transparency, diskless booting, a graphical user interface and, in Domain/OS, interoperability with BSD, System V, and POSIX.
Шаблон:AnchorHardware
An Apollo workstation resembles a modern PC, with a base unit, keyboard, mouse, and screen. Early models are housed in short (about 2 ft high) 19" rack cabinets to be set beside a desk or under a table. The DN300 and later DN330 were designed as integrated units with the system and monitor in one unit. These models fit easily on a desk.
Every Apollo system (even standalone) includes at least one network interface. Originally the only option was the 12 Mbit/s Apollo Token Ring (ATR). Over time, 10 Mbit/s Ethernet was added as an option. It has been stated that the IBM Token Ring was an option but this was never available. The ATR was generally the best choice, since it was extremely scalable; the Ethernet of the time has serious performance loss as extra machines are added to the network, but this is not true of ATR, which can easily have over 100 machines on one network. One drawback is that, unlike Ethernet, one machine failure (which could easily happen with a single faulty connector) stops the entire network. For this reason, Apollo provided an optional (but strongly recommended) network cabling system of bypass switches and quick connect boxes which allow machines to be disconnected and moved without problems. Apollo Token Ring networks used 75 ohm RG-6U coaxial cabling.
Networking
The network orientation of the systems, together with the ATR functionality, enables easy and practicable booting to diskless machines using another machine's OS. In principle, as many machines could be booted from one host as it can cope with; in practice, four diskless machines from one host is about the limit. Provided the correct machine-specific software is installed on the host (again, very easy), any type of machine could be booted from any other. One complication being that a DN10000 could only be booted from another DN10000 or a 68K-based system which had "cmpexe" compound executables installed.
Some systems can have the graphics card removed for use as a servers and the keyboard and mouse are automatically ignored, and the system accessed either across the network, or via a dumb terminal plugged into the machine's serial port. Such a system is designated "DSP" instead of "DN".
Models
The model naming convention is DN (for Domain Node) with a model number. If the system has no display, it is a DSP (for Domain Service Processor).
The first model is the DN416 workstation, later referred to as the DN100 after the green screen was substituted with a black and white screen. This system uses two 68000 processors and implements virtual memory (which the 68000 is not theoretically capable of) by stopping one processor when there is a page fault and having the other processor handle the fault, then release the primary processor when the page fault was handled.
Later models were based on 68010, 68020, 68030 and 68040 processors which had native support for virtual memory. Some workstations had bit-slice CPU implementations that were instruction set compatible with the 68000.
The DSP90 is a fileserver built using a standard Multibus backplane and I/O controllers. The disk controller supports up to four 500MB hard drives. A 9-track tape controller was released.
Early performance models are the DN560 and DN660 which are housed in desk-side cabinets. These can have color graphics cards with graphics accelerators.
The DN300 and later DN330 are integrated desktop systems not much bigger than the included monitor.
In the late 1980s, Apollo introduced a new pair of machines, the DN3000 and DN4000 with 68020 processors,[1] but are housed in IBM PC style cases of the time with IBM-AT compatible ISA expansion slots and PC-compatible disk drives. These became the mainstay of the Apollo range in the mid to late 1980s. In principle, a user or third party can install a standard AT expansion card, but since this requires writing a special device driver, in practice this was very rare. However, the size and design of the boxes make installing or replacing components very easy. A typical system could have between 2 MiB and 32 MiB of memory, a 76 MB, 150 MB or 330 MB (very occasionally 660 MB) hard disk, and 32-bit 68020 or 68030 processor running at 12 MHz to 33 MHz, depending on model. A half-height expansion bay could take either a 5¼-inch floppy disk drive or a QIC-type cartridge tape drive, capacity 30 MB, 45 MB, or 60 MB depending on cartridge. For printer access, the system came with a serial port as standard; a serial/parallel expansion card could provide a parallel printer port if this was required.
The DN3000 and DN4000 were later upgraded to DN3500 and DN4500 with a faster 68030 CPU. The DN3500 was approximately as powerful as the DN4000. A DN5500 with a 68040 was also produced in limited quantities.
A DN2500 workstation was released which was advertised as "4 Mips, 4 MB of memory, for under $4,000". This was a single integrated motherboard that used PC standard DRAM DIMM modules. This was a significant departure from previous designs and those of the competition which had custom memory modules. The motherboard included a high resolution (1280x1024) black and white bitmapped display and SCSI disk interface. The systems included a single AT expansion slot for a network card to allow the system to attach to any of the three supported networks (Apollo Token Ring, IBM Token Ring, or Ethernet)
After HP purchased Apollo Computer, a merged line of workstations that could run either Domain/OS or HP-UX was produced with the name HP/Apollo 425t and HP/Apollo 433s. The 425t is a "pizza box" design with a single network expansion slot. The 433s is a desk-side server systems with multiple expansion slots.
Compatibility
PC compatibility is possible either through software emulation, using the optional product DPCE, or through a plug-in card carrying an Intel 80286 processor. A third-party plug-in card with a 386 was also available.
An Apollo Token Ring network card can be placed in a standard PC and network drivers connect it to a PC SMB (Server Message Block) file server.
Usage
Although Apollo systems are easy to use and administer, they became less cost-effective because the proprietary operating system made software more expensive than Unix software. The 68K processors are slower than the new RISC chips from Sun and Hewlett-Packard. Apollo addressed both problems by introducing the RISC-based DN10000 and Unix-friendly Domain/OS operating system. However, the DN10000, though fast, was extremely expensive, and a reliable version of Domain/OS came too late to make a difference. The increased speed and falling price of PCs ensured the obsolescence of high end systems such as Apollo workstations.
ARM CPU design
When Acorn Computers began designing the ARM 1 CPU in 1984 they used a single Apollo DN 600 workstation to do VLSI design with engineers taking shifts to use the machine. Later in the project they acquired additional workstations.[2]
Acquisition
In 1989, Hewlett-Packard acquired Apollo. They later released the DN2500 series workstation, a cheap alternative to the DN3x00/4x00 series, and later still the HP 9000 Series 400 line, which could run either HP's own flavor of Unix, HP-UX, or Domain/OS. In this case, the choice had to be made at time of purchase, partly because HP-UX and Domain/OS functionality required different keyboards and mice.
References
External links
