Complex sentence: The competition was originated by posters to the comp.sys.sinclair newsgroup and was inspired by the Cascade Cassette 50 compilation as well as Rich Pelley's Crap Game Corner from Your Sinclair Magazine.
Split into simpler sentences: The competition was originated by posters to the comp.sys.sinclair newsgroup and was inspired by the Cascade Cassette 50 compilation. It was also influenced by Rich Pelley's Crap Game Corner from Your Sinclair Magazine.