Micron Electronics Inc., a direct seller of personal computers, said it named Joel Kocher, its president and chief operating officer since January, as chairman and chief executive, replacing Joe Daltoso, who is retiring at age 36. Daltoso, who held the top positions since Micron Electronics' inception in 1995, said he wants to spend more time with his family. He will provide consulting services to the Nampa, Idaho-based company for an indefinite time to ensure a smooth transition. The company is 64% owned by Micron Technology Inc., one of the top makers of computer memory chips. Before joining Micron, Kocher, 42, was president of Power Computing Inc., the first company to license and market clones of Apple Computer Inc.'s Macintosh machines. Separately, Micron Technology said it will acquire closely held Rendition Inc. for about $88.3 million in stock as Micron expands into the graphics-accelerators market. Sunnyvale, Calif.-based Rendition has 95 employees and would not disclose its 1997 sales. Micron Electronics shares rose 31 cents to close at $10.94 on Nasdaq. Micron Technology rose 50 cents to close at $23.88 on the New York Stock Exchange.