Controversy with Sierra over royalties for the PC port of this game led the series creator Richard Garriott to start his own company , Origin Systems .
It was also the only official Ultima game published by Sierra On - Line .
Controversy with Sierra On - Line over royalties for the PC port of this game led the series creator Richard Garriott to start his own company , Origin Systems .
It was also the only official Ultima game published by Sierra On - Line .