|
Univac 1107
The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Series. The solid-state 1107 model number was in the same sequence as the earlier vacuum-tube computers, but the early computers were not compatible with the solid-state successors. Architecture Data formats * Fixed-point, either integer or fraction **Whole word – 36-bit (ones' complement) **Half word – two 18-bit fields per word (unsigned or ones' complement) **Third word – three 12-bit fields per word (ones' complement) **Quarter word – four 9-bit fields per word (unsigned) **Sixth word – six 6-bit fields per word (unsigned) *Floating point **Single precision – 36 bits: sign bit, 8-bit characteristic, 27-bit mantissa **Double precision – 72 bits: sign bit, 11-bit characteristic, 60-bit mantissa *Alphanumeric ** FIELDATA – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are , which severely limited its scope. All modern computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set. The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding. ASCII is one of the IEEE milestones. Overview ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American National Standards I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1103
The UNIVAC 1103 or ERA 1103, a successor to the UNIVAC 1101, was a computer system designed by Engineering Research Associates and built by the Remington Rand corporation in October 1953. It was the first computer for which Seymour Cray was credited with design work. History Even before the completion of the ''Atlas'' (UNIVAC 1101), the Navy asked Engineering Research Associates to design a more powerful machine. This project became Task 29, and the computer was designated ''Atlas II''. In 1952, Engineering Research Associates asked the Armed Forces Security Agency (the predecessor of the NSA) for approval to sell the ''Atlas II'' commercially. Permission was given, on the condition that several specialized instructions would be removed. The commercial version then became the UNIVAC 1103. Because of security classification, Remington Rand management was unaware of this machine before this. The first commercially sold UNIVAC 1103 was sold to the aircraft manufacturer Convair, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1102
The UNIVAC 1102 or ERA 1102 was designed by Engineering Research Associates for the United States Air Force's Arnold Engineering Development Center in Tullahoma, Tennessee in response to a request for proposal issued in 1950. The Air Force needed three computers to do data reduction for two wind tunnels and an engine test facility. The 1102 was a variant of the UNIVAC 1101, using its 24-bit word and a smaller (only 8,192 words) drum memory. The machine had 2,700 vacuum tubes, weighed , and occupied of floor area. The computers were connected to data channels coming from the wind tunnels and the engine facility. There were five typewriters for printed output, five paper tape punches, and four pen plotters to produce graphs. The three computers and related peripherals were delivered between July 1954 and July 1956 at a total price of $1,400,000. Software for the computers was developed entirely at the Arnold Engineering Development center. All programming was done in machine c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering Research Associates
Engineering Research Associates, commonly known as ERA, was a pioneering computer firm from the 1950s. ERA became famous for their numerical computers, but as the market expanded they became better known for their drum memory systems. They were eventually purchased by Remington Rand and merged into their UNIVAC department. Many of the company founders later left to form Control Data Corporation. Wartime origins of ERA The ERA team started as a group of scientists and engineers working for the US Navy during WWII on code-breaking, a division known as the Communications Supplementary Activity - Washington (CSAW). After the war budgets were cut for most military projects, including CSAW. Joseph Wenger of the Navy's cryptoanalytic group was particularly worried that the CSAW team would spread to various companies and the Navy would lose their ability to quickly design new machines. Post-war organization Wenger and two members of the CSAW team, William Norris and Howard Engstrom, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drum Memory
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. For many early computers, drum memory formed the main working memory of the computer. It was so common that these computers were often referred to as ''drum machines''. Some drums were also used as secondary storage as for example various IBM drum storage drives. Drums were displaced as primary computer memory by magnetic core memory, which offered a better balance of size, speed, cost, reliability and potential for further improvements. Drums in turn were replaced by hard disk drives for secondary storage, which were both less expensive and offered denser storage. The manufacturing of drums ceased in the 1970s. Technical design A drum memory or drum storage unit contained a large metal cylinder, coated on the outside surface with a ferromagnetic recording material. It could be considered the precursor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accumulator (computing)
In a computer's central processing unit (CPU), the accumulator is a register in which intermediate arithmetic logic unit results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory, perhaps only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like an accumulator because the technology used for the large main memory is slower (but cheaper) than that used for a register. Early electronic computer systems were often split into two groups, those with accumulators and those without. Modern computer systems often have multiple general-purpose registers that can operate as accumulators, and the term is no longer as common as it once was. However, to simplify their design, a number of special-purpose processors still use a single accumulator. Basic concept Mathematical operations often take place i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Register
An index register in a computer's CPU is a processor register (or an assigned memory location) used for pointing to operand addresses during the run of a program. It is useful for stepping through strings and arrays. It can also be used for holding loop iterations and counters. In some architectures it is used for read/writing blocks of memory. Depending on the architecture it maybe a dedicated index register or a general-purpose register. Some instruction sets allow more than one index register to be used; in that case additional instruction fields may specify which index registers to use. Generally, the contents of an index register is added to (in some cases subtracted from) an ''immediate'' address (that can be part of the instruction itself or held in another register) to form the "effective" address of the actual data (operand). Special instructions are typically provided to test the index register and, if the test fails, increments the index register by an immediate con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octal
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. This is to say that 10octal represents eight and 100octal represents sixty-four. However, English, like most languages, uses a base-10 number system, hence a true octal system might use different vocabulary. In the decimal system, each place is a power of ten. For example: : \mathbf_ = \mathbf \times 10^1 + \mathbf \times 10^0 In the octal system, each place is a power of eight. For example: : \mathbf_8 = \mathbf \times 8^2 + \mathbf \times 8^1 + \mathbf \times 8^0 By performing the calculation above in the familiar decimal system, we see why 112 in octal is equal to 64+8+2=74 in decimal. Octal numerals can be easily converted from binary representations (similar to a quaternary numeral system) by grouping consecutive binary digits into groups of three (starting from the right, for integers). For example, the binary representation for decimal 74 is 1001010. Two zeroes ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1106
The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Series. The solid-state 1107 model number was in the same sequence as the earlier vacuum-tube computers, but the early computers were not compatible with the solid-state successors. Architecture Data formats * Fixed-point, either integer or fraction **Whole word – 36-bit (ones' complement) **Half word – two 18-bit fields per word (unsigned or ones' complement) **Third word – three 12-bit fields per word (ones' complement) **Quarter word – four 9-bit fields per word (unsigned) **Sixth word – six 6-bit fields per word (unsigned) *Floating point **Single precision – 36 bits: sign bit, 8-bit characteristic, 27-bit mantissa **Double precision – 72 bits: sign bit, 11-bit characteristic, 60-bit mantissa *Alphanumeric ** FIELDATA – UNIV ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1108
The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Series. The solid-state 1107 model number was in the same sequence as the earlier vacuum-tube computers, but the early computers were not compatible with the solid-state successors. Architecture Data formats * Fixed-point, either integer or fraction **Whole word – 36-bit (ones' complement) **Half word – two 18-bit fields per word (unsigned or ones' complement) **Third word – three 12-bit fields per word (ones' complement) **Quarter word – four 9-bit fields per word (unsigned) **Sixth word – six 6-bit fields per word (unsigned) *Floating point **Single precision – 36 bits: sign bit, 8-bit characteristic, 27-bit mantissa **Double precision – 72 bits: sign bit, 11-bit characteristic, 60-bit mantissa *Alphanumeric ** FIELDATA – U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
