The study will begin with 10 patients with AIDS, 10 with ARC, and 10 with asymptomatic HIV infection taking DS by mouth 3 times a day for 24 weeks. If the initial dose of DS is tolerated without significant side effects, the next group of patients will receive a higher dose. A third group of patients will be given either a higher or lower dose depending on the results of the earlier groups. Patients will be evaluated every other week for 12 weeks, then monthly for the remaining 16 weeks. Patients will have the option of continuing DS until the entire study is completed if the drug is well tolerated. Inhaled pentamidine for the prevention of Pneumocystis carinii pneumonia is allowed, but other investigational drugs are not. Drug effects on the HIV virus, immune function, and clinical condition will be monitored during the periodic evaluations.