[1][2][3] Sega imported second-hand machines that required frequent maintenance.
According to former Sega director Akira Nagai, this is what led to the company into developing their own games.
[5] The company prospered from the arcade game boom of the late 1970s, with revenues climbing to over US$100 million by 1979.
[189] Subsequent video-based games such as Pong-Tron (1973), Fonz (1976), and Monaco GP (1979) used discrete logic boards without a CPU microprocessor.
[191] Some titles, such as Zaxxon (1982) were developed externally from Sega, a practice that was not uncommon at the time.