GURPS CthulhuPunk (1995)

From publisher blurb:

"Ancient Horror Crawls Into the Dark Future"

The classic horror of the Cthulhu Mythos meets the dark future of cyberpunk . . . CthulhuPunk! The investigators now have supercomputers, cyborged bodies, and deadly new hand weapons – but the breakdown of society has given the malevolent entities of the Mythos new breeding grounds for corruption and decay.

Produced in cooperation with Chaosium, Inc., GURPS CthulhuPunk provides a complete game world, as well as all the important entities, monsters, spells and malevolent tomes from Chaosium's Call of Cthulhu, converted into GURPS terms.