Pioneer Sparcsystem builder Opus Systems Inc, Mountain View, California, is finally calling it quits with whatever remains of its Sparc clone business and says it is retreating back to its SparcCard personal computer add-in boards. A few weeks ago it auctioned off a lot of its furniture and fixtures as unnecessary to the kind of business it would be doing. It is also believed to have sold off a bunch of Sparc motherboards on very aggressive terms. The downsizing cost it Jim Katzman, the big-time venture capitalist who came in as president back in March to run the joint. Opus declined to say how many people remain with the company or how many boxes it actually put in the field. It is making arrangements outside for continued support of its clone customers. Apparently it is still hoping to do something with some of the software it has developed internally.