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High-level Language Computer Architecture
A high-level language computer architecture (HLLCA) is a computer architecture designed to be targeted by a specific high-level programming language (HLL), rather than the architecture being dictated by hardware considerations. It is accordingly also termed language-directed computer design, coined in and primarily used in the 1960s and 1970s. HLLCAs were popular in the 1960s and 1970s, but largely disappeared in the 1980s. This followed the dramatic failure of the Intel 432 (1981) and the emergence of optimizing compilers and reduced instruction set computer (RISC) architectures and RISC-like complex instruction set computer (CISC) architectures, and the later development of just-in-time compilation (JIT) for HLLs. A detailed survey and critique can be found in . HLLCAs date almost to the beginning of HLLs, in the Burroughs large systems (1961), which were designed for ALGOL 60 (1960), one of the first HLLs. The best known HLLCAs may be the Lisp machines of the 1970s and 1980s, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Computer Architecture
In computer science and computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the description may include the instruction set architecture design, microarchitecture design, logic design, and implementation. History The first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine. While building the computer Z1 in 1936, Konrad Zuse described in two patent applications for his future projects that machine instructions could be stored in the same storage used for data, i.e., the stored-program concept. Two other early and important examples are: * John von Neumann's 1945 paper, First Draft of a Report on the EDVAC, which described an organization of logical elements; and *Alan Turing's more detailed ''Proposed Electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Tokenization (lexical Analysis)
Lexical tokenization is conversion of a text into (semantically or syntactically) meaningful ''lexical tokens'' belonging to categories defined by a "lexer" program. In case of a natural language, those categories include nouns, verbs, adjectives, punctuations etc. In case of a programming language, the categories include identifiers, operators, grouping symbols, data types and language keywords. Lexical tokenization is related to the type of tokenization used in large language models (LLMs) but with two differences. First, lexical tokenization is usually based on a lexical grammar, whereas LLM tokenizers are usually probability-based. Second, LLM tokenizers perform a second step that converts the tokens into numerical values. Rule-based programs A rule-based program, performing lexical tokenization, is called ''tokenizer'', or ''scanner'', although ''scanner'' is also a term for the first stage of a lexer. A lexer forms the first phase of a compiler frontend in processing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Burroughs Medium Systems
The Burroughs B2500 through Burroughs B4900 was a series of mainframe computers developed and manufactured by Burroughs Corporation in Pasadena, California, United States, from 1966 to 1991. They were aimed at the business world with an instruction set optimized for the COBOL programming language. They were also known as Burroughs Medium Systems, by contrast with the Burroughs Large Systems and Burroughs Small Systems. History and architecture First generation The B2500 and B3500 computers were announced in 1966. They operated directly on COBOL-68's primary decimal data types: strings of up to 100 digits, with one EBCDIC or ASCII digit character or two 4-bit binary-coded decimal BCD digits per byte. Portable COBOL programs did not use binary integers at all, so the B2500 did not either, not even for memory addresses. Memory was addressed down to the 4-bit digit in big-endian style, using 5-digit decimal addresses. Floating point numbers also used base 10 rather than some b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Burroughs Large Systems
The Burroughs Large Systems Group produced a family of large 48-bit computing, 48-bit mainframe computer, mainframes using stack machine instruction sets with dense Syllable (computing), syllables.E.g., 12-bit syllables for B5000, 8-bit syllables for B6500 The first machine in the family was the B5000 in 1961, which was optimized for compiling ALGOL 60 programs extremely well, using single-pass compilers. The B5000 evolved into the B5500 (disk rather than drum) and the B5700 (up to four systems running as a cluster). Subsequent major redesigns include the B6500/B6700 line and its successors, as well as the separate B8500 line. In the 1970s, the Burroughs Corporation was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems. Each division's product line grew from a different concept for how to optimize a computer's instruction set for particular programming languages. "Burroughs Large Systems" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
