Setac Inc., a Defense Department contractor with offices in Reston, has promoted Ronald M. Shields to group vice president for systems engineering. A career Navy officer, Shields was previously division general manager.

Genicom Corp., a supplier of computer printers in Waynesboro, has appointed James B. Towell to the new position of vice president for sales. He was formerly with the Qume Corp., an ITT subsidiary.

Maryland Computer Services, which produces computer aids for the blind and visually impaired, has named Dave Witter manager of dealer sales for enabling products. Witter, who has 10 years of experience with enabling technologies for the handicapped, previously taught at the Atlanta Area Services for the Blind.

Pace Applied Technology Inc. has appointed Guy M. Reeve to head the Manassas firm's new federal government and special projects division.

Infocel, the Rockville computer products firm, said that Stephen A. Small has joined the firm as vice president for sales. He was formerly a regional sales manager with Control Data Corp.

Mark D. Grant, a former partner of a local accounting firm, has formed a new firm, Business Systems Support Group Inc., to offer computer hardware, software and training that will specialize in accounting and financial control systems.

Lykes, Duff & Sarver, the Arlington-based financial consulting and software company, has tapped Richard M. M. McConnell as executive vice president and the firm's fourth partner. McConnell, formerly senior vice president with the bank consulting firm of Golembe Associates Inc., will head the firm's product development and marketing efforts.