The attitudes of high school students toward the use of microcomputers were examined in terms of causal attributions, i.e., student perceptions of the causes of academic performance. The subjects for the study were 171 male and female students, representing 102 white and 69 minority students who were enrolled in a large city high school. The majority of these students had already completed computer coursework or had other previous computer experience. Two scales, the Computer Attitude Scale and Computer Attribution Scale, were developed from the Fennema-Sherman Mathematics Attitude Scale and the Mathematics Attribution Scale of Fennema, Wolleat, and Pedro, respectively, in order to examine the use and study of computers in this population. The primary focuses of this study--sex and ethnic differences in computer attitudes and computer attributions--were investigated using the multivariate analysis of variance technique. Results indicated that: (1) while there were no ethnic group differences in high school students' attributions of success or failure in using computers, there were significant sex differences in computer attributions, with males attributing their successes in using computers to their own abilities, and females attributing their success to uncontrolled environmental factors; (2) all groups involved had fairly positive attitudes toward computers; (3) both sex and ethnic group differences existed in computer attitudes, with white students perceiving computers as more enjoyable and challenging than minority students, and male students and white students tending to have a more positive attitude toward learning computer skills than female and minority students. Three tables are appended. (39 references) (CGD)