0000040729-98-000150 424B3 1 19980814 NONE GENERAL MOTORS ACCEPTANCE CORP 0000040729 6141 380572512 NY 1231 424B3 33 333-48207 98690500 3044 W GRAND BLVD DETROIT MI 48202 3135565000 424B3 1 000004072998000150-001-seq1-424b3.txt SMARTNOTE NO. 21