Browse Prior Art Database

Digital Data Storage Using Video Disc

IP.com Disclosure Number: IPCOM000052846D
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Kennedy, PJ: AUTHOR

Abstract

This system utilizes video disc mass storage of digital data in conjunction with intermediate buffer storage to enable fast access of the data by a processor. Video disc technology permits high-density storage of images and sound on a plastic disc. A disc player optically scans the recorded information to play out picture and sound on a television set.

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Digital Data Storage Using Video Disc

This system utilizes video disc mass storage of digital data in conjunction with intermediate buffer storage to enable fast access of the data by a processor. Video disc technology permits high-density storage of images and sound on a plastic disc. A disc player optically scans the recorded information to play out picture and sound on a television set.

One 60-minute video disc has the theoretical capacity of 108,000 frames. This is based on 30 frames/second x 60 seconds/minute x 60 minutes/hour = 108,000. A representative system has a 30-minute disc and can randomly access 54,000 frames. Assuming the most conservative case of one picture element representing one bit, there are 500 x 500 picture elements (pixels) per frame. This is equal to 2.5(10)/5/ pixels/ frame x 5.4(10/4/) frame/disc =
1.35(10)/10/ bits/disc or 3,375(10/6/) bytes. Ten bits or more per picture element are theoretically possible.

A characteristic of video disc systems is that access to data may take up to 5 seconds, which may be too slow for some applications. The drawing illustrates a scheme for compensating for this. The system includes a controller 1, disc player 2, processor 3, and buffer registers 4a-4n. Controller 1 reads out a given frame while simultaneously conditioning one of the gates 5a-5n to allow a frame of data to be stored in the associated buffer. While that data is being used by the processor, the next frame is transferred to another buffe...