Английская Википедия:Harvard biphase

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Шаблон:Notability

Harvard biphase is a magnetic run length code for encoding magnetic tape.[1] It is one of the formats employed in forming the digital bits of logic one and logic zero, along with non-return-to-zero (NRZ) and bipolar-return-to-zero (RZ) formats.[2] Each bit in the Harvard biphase format undergoes change at its trailing edge and this transpires either from high to zero or zero to high independently of its value.[2]

FDR

Harvard biphase has previously been used for digital flight data recorder (FDR) where 12-bit words per second are recorded onto magnetic tape using Harvard biphase code.[3] The data are encoded in frames and each of these contains a snapshot of the avionics system in the aircraft.[4] For Harvard biphase, a phase transition in the middle of the bit cell indicates that the bit is 1. No transaction indicates that the bit is 0. There is also a phase transition at the start of each bit cell.[5] The ARINC 573 serves as a standard for FDRs that feature continuous data stream encoded in Harvard biphase.[6]

See also

References

  1. Digest of papers: computer peripherals, CPU--benefactor or bottleneck?, IEEE Computer Society, 1974
  2. 2,0 2,1 Шаблон:Cite book
  3. Digest of Papers, Institute of Electrical and Electronics Engineers, 1974
  4. Шаблон:Cite web
  5. Digital Equipment Computer Users Society Digital Equipment Corporation, 1975 - Electronic digital computers
  6. Шаблон:Cite book

Шаблон:Computer-stub