Osamu Tezuka's Shin Tetsuwan Atomu was originally released in Japan in 1980 and America in 1983, as the first full colour animated series featuring the character Mighty Atom / Astro Boy. An English version was recorded in 1983 in America, which primarily played in Australia and America through the 1980s. However, a second English version was produced in 1985 for exclusive use within Anglophone Canadian regions by Cinélume Postproduction Inc. 
This Canadian English version was never released on home video and has since become extremely rare. As of 24 November 2018, only 6 of 51 episodes have been recovered and released online.
The dubbed audio was originally recorded in late 1985 in Montreal, as described by Astro's voice actor Stephen Bednarski. Early Canadian copyright laws did not require dub actors to be listed in credits, so most of the Canadian English cast is unknown. Actors have only been previously identified by recognizing their voices from previous roles. Janice Chaikelson, Rick Jones, and Walter Massey have been identified as additional voices.
Unlike the American English dub, the Canadian version was highly edited for violence, with entire sequences being re-edited. One such example was in the episode "Light Ray Robot," where the original ending - an invisible robot runs away with a bomb and explodes in a forest - was edited with spliced in footage to make it seem as if the bomb failed and never went off. The episode "Save the Carolina-3" originally has a scene with a man being shot in the eyes with a laser, but the footage was reorganized to completely remove scenes of him being shot, in pain, or even with his eyes bandaged for the rest of the episode. These edits are identical to those of the French dub, which was known as Astro le Petit Robot and also recorded in Montreal.
Curiously, the Canadian dub uses the American English dub's opening and ending themes, which were sung by the American dubbing cast. This suggests that the show's masters were either licensed from the other English dub production company, or the preexisting English themes were provided by Tezuka Productions' international department.
Almost every character's name was changed, aside from Astro Boy, Atlas, and some background characters. Character name changes include Astro's sister Uran being named "Sarah," and Astro's scientist mentor Dr. Ochanomizu (or Dr. Elefun in American English) being renamed "Professor Peabody." Most famous is the addition of sequences at the end of each episode, where Astro reports his adventure to a computer named Geronimo. There is always one error in his report, which the viewer is encouraged to identify as part of a game. The exact error was never specified in other episodes. Instead, it is left for the viewer to find themselves.
Since it is moderately recent, many older viewers primarily remember the Canadian dub's character names, scenes, and jokes over the ones in the more accessible American version. Amazon.com reviews for the American Astro Boy Anchor Bay and Madman Entertainment DVD releases often contain complaints about not being the version the reviewer remembers.
To date, only six Canadian English episodes have been recovered. Unfortunately, these beta tapes were then wiped and reused for other programming when Astro Boy's syndication period ended.
The French counterpart Astro le Petit Robot is available in full on DVD, but of course, these DVDs only contain the French dub.
Dailymotion user Robotkat has been actively searching for more episodes, and maintains uploads of all six recovered episodes:
- Episode 2: "The Robot Circus"
- Episode 4: "Atlas Lives Again"
- Episode 15: "Astro Fights Aliens" part one, two, and three
- Episode 22: "The Girl From Alsoar"
- Episode 26: "The Time Machine"
- Episode 41: "The Robots Nobody Wanted"