Complex sentence: While in prison, Fender also writes many science fiction novels under another pseudonym, Frank X. Barlow, and works as the chief clerk in the supply room of the prison.
Split into simpler sentences: While in prison, Fender writes many science fiction novels under another pseudonym, Frank X. Barlow, as well. In addition to writing science fiction novels, Fender is the chief clerk in the supply room of the prison.