Ikegami Tsushinki Co., Ltd. (池上通信機株式会社) is a manufacturer of professional video equipment such as cameras and monitors. It was founded on September 10, 1946, and incorporated on February 21, 1948.  In the late 1970s and early 1980s, the company was involved with developing arcade games, primarily for Nintendo.
Ikegami's relationship with Nintendo began when Ikegami was asked by Tokuzo Komai of Nintendo Leisure System to develop arcade games exclusively for Nintendo; per their agreement, Ikegami would develop and manufacture the games, and Nintendo would sell them under its own name.
Among the games Ikegami worked on was Donkey Kong, created as a conversion for Radar Scope, which sold poorly when it came to the United States. Nintendo's Shigeru Miyamoto devised the play mechanics, story, and characters; Ikegami programmed the game and manufactured the boards.
Ikegami signed the development contract for Donkey Kong in April 1981. Nintendo would pay Ikegami ¥10,000,000 for development. The contract also specified that Nintendo was not to copy the program, nor allow a third party to do so. However, the contract did not actually specify who owned the program.
Donkey Kong went on to become an international hit, prompting production of a sequel — Donkey Kong Junior — starting in March 1982. In 1983, Ikegami sued Nintendo, claiming it owned the original Donkey Kong code and that Donkey Kong Junior had been made using said code without Ikegami's permission. The two companies finally settled in 1990; the details of that settlement were not released to the public.
If you look at the tilesets from Congo Bongo, Donkey Kong, and Zaxxon, you will find the then Ikegami logo (see right; below that: the logo as seen on a 1978 Ikegami color Handy Looky viewfinder). It also turns up in Donkey Kong Junior and Super Zaxxon, but Ikegami's involvement with the latter is unknown. (The situation with Donkey Kong Junior was explained earlier; Super Zaxxon is essentially a more challenging version of Zaxxon.)
The following text appears in the main CPU in most versions of Donkey Kong :
CONGRATULATION !IF YOU ANALYSE DIFFICULT THIS PROGRAM,WE WOULD TEACH YOU.*****TEL.TOKYO-JAPAN 044(244)2151 EXTENTION 304 SYSTEM DESIGN IKEGAMI CO. LIM.
- Donkey Kong (Nintendo)
- Radar Scope (Nintendo)
- Tip Top / Congo Bongo (Sega)
- Zaxxon (Sega)
Masumi Akagi's book Sore wa "Pong" kara Hajimatta: Arcade TV Game no Naritachi says Ikegami worked on eight titles and lists six: Block Fever, Space Fever, Sheriff, Space Firebird, Radar Scope, and Donkey Kong. According to Akagi, Ikegami planned and programmed these games, but he notes, "from Space Firebird on, Nintendo became involved in design, and with Donkey Kong, Nintendo became deeply involved in development. After this, Nintendo no longer needed Ikegami’s assistance."
Florent Gorges' book L'Histoire de Nintendo Vol. 1 lists Ikegami as the co-developer of the following games: Block Fever, Space Fever / Space Fever Color / SF-HiSplitter, Space Firebird, Heli Fire, Radar Scope, and Donkey Kong. A later edition of the book lists Ikegami as the sole developer of Space Launcher.
- 1. Akagi, Masumi. Sore wa "Pong" kara Hajimatta: Arcade TV Game no Naritachi. Amusement Tsuushinsha, 2005.
- Excerpt translated by Dimitri