Sun Microsystems Inc’s chief executive Scott McNealy cannot only not make up his mind about who should become president of Sun Microsystems Computer Corp, the company’s hardware business, but the same appears to be true about a president for its chip marketing unit, Sparc Technology Business. Sparc Technology has had only an acting president, Bob Graham, who warned that he was going to leave back in October and finally did over the holidays. Sun was unable to come up with a firm appointment and last week decided to name another acting president, Bert Sutherland, head of Sun Labs, and postpone for six months making Sparc Technology Business a planet.