* Harold E. Miller Jr. has been...

* Harold E. Miller Jr. has been appointed president of Westamerica Computer Services Inc. in Irvine, the data processing service bureau subsidiary of Westcorp. He succeeds Mike Mann, who has left the company. Before joining Westamerica, Miller was vice president of Nissan Motor Acceptance Corp. He has also worked at IBM and spent more than 15 years as a founder and manager of Total Systems Inc., a Texas data-processing service bureau.