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Relating Test Results to Data Reliability of Signal Recording Apparatus

IP.com Disclosure Number: IPCOM000082572D
Original Publication Date: 1975-Jan-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 3 page(s) / 54K

Publishing Venue

IBM

Related People

Ernisse, DJ: AUTHOR [+2]

Abstract

The task of relating device parameter variations to the data reliability of apparatus being designed is an important aspect in the design development of such apparatus, as well as controlling the yield and cost of the manufactured apparatus. In digital signal recorders, particularly of the rotating head type, the parameter interaction of the recorder mechanical construction, the error correction codes, the error control circuits, and medium performance levels requires statistical and coordinative analysis in a programmed computer, preferably on a realtime basis.

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Relating Test Results to Data Reliability of Signal Recording Apparatus

The task of relating device parameter variations to the data reliability of apparatus being designed is an important aspect in the design development of such apparatus, as well as controlling the yield and cost of the manufactured apparatus. In digital signal recorders, particularly of the rotating head type, the parameter interaction of the recorder mechanical construction, the error correction codes, the error control circuits, and medium performance levels requires statistical and coordinative analysis in a programmed computer, preferably on a realtime basis.

Such analysis should point to the appropriateness of parameter selection, adjustment, and the importance of such parameters in achieving desired high- data reliability. Such testing procedures for predicting data reliability should include: detection of data bits read and comparison with a map of bits written while reading only or during recording; evaluation of the independent functional interface connections to host computer systems; realtime multiplexing of error indicating signal occurrences or events with data in error for analyzing and minimizing error sources; understanding and optimizing error pointer circuit efficiency; derivation of suitable error statistics which define desired error correction code performance enabling code selection; providing relative performance comparisons of various magnetic media types, and thus aiding in optimization/selection development; analysis and optimization of circuit performance which includes equalization compensation, feedthrough cancellation in magnetic recording heads, signal demodulation, and detection parameters; and analysis and optimization of medium-to-transducer spacial relationship.

The above-mentioned procedures performed on a realtime basis require high-speed programmed computers. The recording density of newly designed signal recorders is relatively high, yielding a relatively high-data rate such that oscilloscopes and finite memory transient recorders are inadequate for measuring recorder apparatus operation, particularly with respect to assessing statistical reliability of such operations. Further, the parameter interaction is so complex as to belie proper analysis on "primitive" devices.

The drawing illustrates an apparatus interconnection scheme which will measure and correlate a wide variety of recorder parameters in realtime, while determining recorder raw reliability prediction. The programmed computer is an IBM 360 Model 44 programmed for encoding data to be recorded on the digital signal recorder, as well as formatting such data. This CPU has a customized data acquisition consisting of D...