Invade-a-Load

Invade-a-Load was a fast loader routine used in software for Commodore 64 computer. It was used in commercial computer games that were stored on Compact Cassette tape and loaded using the Datassette.
Invade-a-Load allowed the user to play a small clone of the famous "Space Invaders" game while the main game was loading. This initial minigame was loaded in under a minute, providing entertainment while waiting for the actual game to load, which could take a further five to ten minutes. On at least one occasion, a reviewer expressed their preference for Invade-a-Load over the main game itself.
It mostly appeared in games sold in the United Kingdom, as, by the time it was written, the Commodore market in the United States had mostly switched to floppy disk media.
History and use.
The loader was written by Richard Aplin for Mastertronic's own use.
The loader itself has a copyright date of 1987, but the first games that used the loader showed up in 1988. Over the following years, Mastertronic used the loader in dozens of titles.
The loader was also memorable for the soundtrack, originally made by Rob Hubbard for the Mastertronic title "One Man and His Droid".
Patents.
In 1995, Yoichi Hayashi of Namco Ltd. invented a variant of this technique for use with optical disc based platforms such as PlayStation and applied for a patent. was granted in February 1998 and assigned to Namco despite the Invade-a-Load prior art.