The Apple Workgroup Server 9150 is the only Apple Workgroup Server model not based on a desktop Mac. It featured an 80 MHz (speed bumped to 120 MHz in April 1995) PowerPC 601 board in a Quadra 950 style case. The internal bay of the 950 case was filled with a tape backup drive. It has 8MB of RAM (expandable to 264MB). It runs System 7.5 to Mac OS 9.1.