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DF-224
The DF-224 is a space-qualified computer used in space missions from the 1980s. It was built by Rockwell Autonetics. As with many spacecraft computers, the design is very redundant, since servicing in space is at best difficult and often impossible. The configuration had three CPUs, one active and two spares. The main memory consisted of six memory units, each with 8K 24-bit words of plated wire memory, with up to 48K words total. Four memory modules could be powered up at one time, resulting in a maximum of 32K words of available memory, though some applications such as the Hubble Space Telescope used fewer memory banks to allow for graceful failure modes. There were three I/O processors, one operational and two backups. The power supply consisted of 6 independent power converters, with overlapping coverage of the operating functions. The processor used fixed-point arithmetic with a two's complement format. Compared to computers that came later, the DF-224 was big and sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DF-224
The DF-224 is a space-qualified computer used in space missions from the 1980s. It was built by Rockwell Autonetics. As with many spacecraft computers, the design is very redundant, since servicing in space is at best difficult and often impossible. The configuration had three CPUs, one active and two spares. The main memory consisted of six memory units, each with 8K 24-bit words of plated wire memory, with up to 48K words total. Four memory modules could be powered up at one time, resulting in a maximum of 32K words of available memory, though some applications such as the Hubble Space Telescope used fewer memory banks to allow for graceful failure modes. There were three I/O processors, one operational and two backups. The power supply consisted of 6 independent power converters, with overlapping coverage of the operating functions. The processor used fixed-point arithmetic with a two's complement format. Compared to computers that came later, the DF-224 was big and sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as Computer program, programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the Computer hardware, hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of Programmable logic controller, industrial and Consumer electronics, consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rockwell International
Rockwell International was a major American manufacturing conglomerate involved in aircraft, the space industry, defense and commercial electronics, components in the automotive industry, printing presses, avionics and industrial products. Rockwell International's predecessor was Rockwell Manufacturing Company, founded in 1919 by Willard Rockwell. In 1968, Rockwell Manufacturing Company included 7 operating divisions manufacturing industrial valves, German 2-cycle motors, power tools, gas and water meters. In 1973, it was combined with the aerospace products and renamed Rockwell International. At its peak, Rockwell International was No. 27 on the Fortune 500 list, with assets of over $8 billion, sales of $27 billion and 115,000 employees. History Rockwell Manufacturing Company Boston-born Willard Rockwell (1888–1978) made his fortune with the invention and successful launch of a new bearing system for truck axles in 1919. He merged his Oshkosh, Wisconsin-base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plated Wire Memory
Plated-wire memory is a variation of core memory developed by Bell Laboratories in 1957. Its primary advantage was that it could be machine-assembled, which potentially led to lower prices than the almost always hand-assembled core. Instead of threading individual ferrite cores on wires, plated-wire memory used a grid of wires coated with a thin layer of iron–nickel alloy called permalloy. The magnetic field normally stored in the ferrite core was instead stored on the wire itself. Operation was generally similar to core memory, with the wire itself acting as the data line, and the magnetic domains providing the individual bit locations defined by address (word) lines running on either side of (and perpendicular to) the data wire. Early versions operated in a destructive read mode, requiring a write after read to restore data. Non-destructive read mode was possible, but this required much greater uniformity of the magnetic coating. Improvements in semiconductor RAM chips pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault-tolerant System
Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the severity of the failure, as compared to a naively designed system, in which even a small failure can cause total breakdown. Fault tolerance is particularly sought after in high-availability, mission-critical, or even life-critical systems. The ability of maintaining functionality when portions of a system break down is referred to as graceful degradation. A fault-tolerant design enables a system to continue its intended operation, possibly at a reduced level, rather than failing completely, when some part of the system fails. The term is most commonly used to describe computer systems designed to continue more or less fully operational with, perhaps, a reduction in throughput or an increase in response time in the event of some partial f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-point Arithmetic
In computing, fixed-point is a method of representing fractional (non-integer) numbers by storing a fixed number of digits of their fractional part. Dollar amounts, for example, are often stored with exactly two fractional digits, representing the cents (1/100 of dollar). More generally, the term may refer to representing fractional values as integer multiples of some fixed small unit, e.g. a fractional amount of hours as an integer multiple of ten-minute intervals. Fixed-point number representation is often contrasted to the more complicated and computationally demanding floating-point representation. In the fixed-point representation, the fraction is often expressed in the same number base as the integer part, but using negative powers of the base ''b''. The most common variants are decimal (base 10) and binary (base 2). The latter is commonly known also as binary scaling. Thus, if ''n'' fraction digits are stored, the value will always be an integer multiple of ''b' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two's Complement
Two's complement is a mathematical operation to reversibly convert a positive binary number into a negative binary number with equivalent (but negative) value, using the binary digit with the greatest place value (the leftmost bit in big- endian numbers, rightmost bit in little-endian numbers) to indicate whether the binary number is positive or negative (the sign). It is used in computer science as the most common method of representing signed (positive, negative, and zero) integers on computers, and more generally, fixed point binary values. When the most significant bit is a one, the number is signed as negative. . Two's complement is executed by 1) inverting (i.e. flipping) all bits, then 2) adding a place value of 1 to the inverted number. For example, say the number −6 is of interest. +6 in binary is 0110 (the leftmost most significant bit is needed for the sign; positive 6 is not 110 because it would be interpreted as -2). Step one is to flip all bits, yielding 1001. St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 80486
The Intel 486, officially named i486 and also known as 80486, is a microprocessor. It is a higher-performance follow-up to the Intel 386. The i486 was introduced in 1989. It represents the fourth generation of binary compatible CPUs following the 8086 of 1978, the Intel 80286 of 1982, and 1985's i386. It was the first tightly- pipelined x86 design as well as the first x86 chip to include more than one million transistors. It offered a large on-chip cache and an integrated floating-point unit. A typical 50 MHz i486 executes around 40 million instructions per second (MIPS), reaching 50 MIPS peak performance. It is approximately twice as fast as the i386 or i286 per clock cycle. The i486's improved performance is thanks to its five-stage pipeline with all stages bound to a single cycle. The enhanced FPU unit on the chip was significantly faster than the i387 FPU per cycle. The intel 80387 FPU ("i387") was a separate, optional math coprocessor that was installed in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RM-81 Agena
The RM-81 Agena was an American rocket upper stage and satellite bus which was developed by Lockheed Corporation initially for the canceled WS-117L reconnaissance satellite program. Following the split-up of WS-117L into SAMOS and Corona for image intelligence, and MIDAS for early warning, the Agena was later used as an upper stage, and an integrated component, for several programs, including Corona reconnaissance satellites and the Agena Target Vehicle used to demonstrate rendezvous and docking during Project Gemini. It was used as an upper stage on the Atlas, Thor, Thorad and Titan IIIB rockets, and considered for others including the Space Shuttle and Atlas V. A total of 365 Agena rockets were launched between February 28, 1959 and February 1987. Only 33 Agenas carried NASA payloads and the vast majority were for DoD programs. On some missions, the payload was built directly into the Agena, which provided it with electric power, communications and three-axis stabilization. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM RAD6000
The RAD6000 radiation-hardened single-board computer, based on the IBM RISC Single Chip CPU, was manufactured by IBM Federal Systems. IBM Federal Systems was sold to Loral, and by way of acquisition, ended up with Lockheed Martin and is currently a part of BAE Systems Electronic Systems. RAD6000 is mainly known as the onboard computer of numerous NASA spacecraft. History The radiation-hardening of the original RSC 1.1 million-transistor processor to make the RAD6000's CPU was done by IBM Federal Systems Division working with the Air Force Research Laboratory. , there are 200 RAD6000 processors in space on a variety of NASA, United States Department of Defense and commercial spacecraft, including: * Mars Exploration Rovers ( ''Spirit'' and ''Opportunity'') * Deep Space 1 probe * Mars Polar Lander and Mars Climate Orbiter * Mars Odyssey orbiter * Spitzer Infrared Telescope Facility * MESSENGER probe to Mercury * STEREO Spacecraft * IMAGE/Explorer 78 MIDEX spacecraft * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD750
The RAD750 is a radiation-hardened single-board computer manufactured by BAE Systems Electronics, Intelligence & Support. The successor of the RAD6000, the RAD750 is for use in high-radiation environments experienced on board satellites and spacecraft. The RAD750 was released in 2001, with the first units launched into space in 2005. Technology The CPU has 10.4 million transistors, an order of magnitude more than the RAD6000 (which had 1.1 million). It is manufactured using either 250 or 150 nm photolithography and has a die area of 130 mm2. It has a core clock of 110 to 200 MHz and can process at 266 MIPS or more. The CPU can include an extended L2 cache to improve performance. The CPU can withstand an absorbed radiation dose of 2,000 to 10,000 grays (200,000 to 1,000,000 rads), temperatures between −55 ° C and 125 °C, and requires 5 watts of power. The standard RAD750 single-board system (CPU and motherboard) can withstand 1,00 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
