File:Bbc-computer-originated-world-uncoloured-half-rotation.gif

Bbc-computer-originated-world-uncoloured-half-rotation.gif(143 × 205 pixels, file size: 592 KB, MIME type: image/gif, looped, 55 frames, 5.5 s)

Summary edit

Media data and Non-free use rationale
Description Underlying frames for the BBC Computer Originated World television ident. The BBC COW hardware generator pushed the limits of what was possible for a full framerate generated image. The CPU capabilities and ROM storage were limited by the technology of the early 1980s. The rotating world was not stored as the colours seen on-screen, but as a minimal grayscale representation and only coloured at play out.

When the globe had rotated 180 degrees the "back" and "front" colours were switched for the next 180 degrees of play out. The recorded frames were only a subset of the full television frame displayed, and were in-turn stored in the ROM used run-length encoding to save space.

Author or
copyright owner
BBC
Source (WP:NFCC#4) A skip (containing the ROM image of discarded hardware COW generator)
Date of publication c.1984–1985
Use in article (WP:NFCC#7) Computer Originated World
Purpose of use in article (WP:NFCC#8) For visual identification of the object of the article. The article as a whole is dedicated specifically to a discussion of this work.
Not replaceable with
free media because
(WP:NFCC#1)
n.a.
Minimal use (WP:NFCC#3) Necessary to demonstrate operation of the system. The image is low-resolution and contains frames amounting to only half the rotation that a viewer would have seen.
Respect for
commercial opportunities
(WP:NFCC#2)
The British Broadcasting Corporation stopped using the BBC1 ident in 1991, and the related variant for BBC World in 1994.
Other information The animation differs from what was displayed on-screen and is necessary to demonstrate the inner-workings of operation the system under discussion. The animation is a crop of full-frame, and prior to colourisation. The .gif contains one-half-of-rotation only and is played back at a slower frame-rate to help show the working of the system. PAL television uses a pixel aspect ratio of 5:4, leading the globe to appear non-circular.
Fair useFair use of copyrighted material in the context of Computer Originated World//en.wikipedia.org/wiki/File:Bbc-computer-originated-world-uncoloured-half-rotation.giftrue

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Date/TimeThumbnailDimensionsUserComment
current09:13, 9 December 2013Thumbnail for version as of 09:13, 9 December 2013143 × 205 (592 KB)Sladen (talk | contribs)Uploading a non-free work, as object of commentary using File Upload Wizard
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