Increase the remission induction rate to greater than 85% in children with untreated acute myelogenous leukemia (AML) or myelodysplastic syndromes (MDS) by replacing daunorubicin (DNR) with idarubicin (IDA) in intensively timed DCTER chemotherapy (dexamethasone, cytarabine (ARA-C), thioguanine, etoposide, and daunorubicin) in the first 4 days of each course.