Apparatus and method for data recording with peak shift compensation
US4000513A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1975 |
| Grant date | Dec 28, 1976 |
| Priority date | — |
| Expiry date | Jul 28, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10212
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A data writing and recording system and method and circuitry therefor is disclosed in which peak shift due to pulse crowding of data recorded on a magnetic medium is substantially reduced. The recorded data time pattern is preemphasized to compensate for peak shift such that an optimum magnetic pattern is recorded on the magnetic medium. The preemphasis of recorded peak shift errors is accomplished either by delaying or advancing the time when a particular peak shifted data transition caused by a known encoding data pattern will occur. NRZI type encoded data is coupled to a first serial to parallel shift register and clocked through to a ROM at a frequency corresponding to the data bit cell width. The ROM examines the incoming data, which is also clocked from an intermediate stage in the first shift register to a second serial-to-parallel shift register having a data clock frequency substantially greater than the data clock frequency of the first shift register. The second shift register operates as a multi-tapped delay line having a multiplexed output selected by a look-up table programmed into the ROM in accordance with a determination by the ROM of the degree incoming peak shift…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.