From Sega Retro
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Pioneer Corporation (パイオニア株式会社) is a Japanese multinational corporation which specializes in consumer electronics and digital entertainment products. During the mid to late 1990s, the company published Sega Mega LD and Sega Saturn games through it's LaserDisc-focused subsidiary Pioneer LDC.
The company developed the SEED Television platform, which could be expanded with the Sega SG-1000 and Sega SC-3000-compatible Pioneer TV Video Game Pack SD-G5. This idea of expandability would be further developed into the Pioneer LaserActive, which featured the Sega Mega Drive and Sega Mega-CD-compatible Sega PAC, and which also established a new LaserDisc-based format, Sega Mega LD.
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