Friday night, after the close of the Stock Market, Apple Computer announced that it would lose between $100 million and $150 million for its first quarter. The company blames slow sales of the Performa line and a shortage of PowerBooks. Performas are Apple's Macs for the home market; PowerBooks are portable computers that generally sell very well. Apple's sales slid 34 percent from the same quarter last year, when they lost $69 million. In September, Apple's share of the global computer market slipped to 5.4%. Apple will release final figures on January 15