Edward J. Arnold has been named president and chief operating officer of Dense-Pac Microsystems Inc. He replaces Donald R. Wilshe, who had filled the position since November and will now be executive vice president of marketing and development. Arnold has also been appointed as the sixth member of the company’s board of directors.

Arnold previously was with Illinois-based Gould Inc.'s Defense Systems Group, which he joined in 1972 as senior program manager. He held a number of management positions with Gould and in 1981 he was appointed the company’s vice president of operations and applied engineering. In 1985 he became vice president of avionics at the company’s NAVCOM Systems division.

Dense-Pac Microsystems is a Garden Grove-based maker of memory modules for military, aerospace and industrial uses.