If parking space seems scarce this morning or your favorite downtown restaurant is turning away reservations, blame it on computers.

This week Washington is the site of two major annual electronic events. The Federal Computer Conference, geared primarily to federal automated data-processing professionals, begins today at the Sheraton Washington. The Mid-Atlantic Computer and Office Equipment Exposition, with exhibits designed for just about everyone, opens Thursday at the D.C. Armory.

More than 11,000 data-processing professionals from across the country are expected to attend the federal conference, which is sponsored by Federal Education Programs, a private-sector organization. This year the conference features nearly 150 exhibitors, including virtually all of the industry's leading companies, developing the theme "An Agenda for Managing Change."

Assistant Secretary of Defense Jack R. Borsting, who serves as chief financial officer for the secretary of Defense, is today's featured luncheon speaker. His topic: "Managing Change: Challenge of the '80s." Borsting is the department's top data-processing policy official and is responsible for all nontactical computer procurement.

Also today there are eight concurrent, day-long seminars, which should provide an overview of major developments in data communications, distributed processing, data-base management and fourth-generation computer languages. Leading authorities will outline the latest practices in security/disaster planning and product management, as well as the strategies and tools needed for successful federal data-processing procurement.

The main conference program gets started tomorrow and continues through Wednesday, with federal experts discussing changes in policy, agency mission and technology in 34 separate, comprehensive sessions. Topics as diverse as the Federal Paperwork Reduction Act, waste and fraud, and developments with microprocessor, data-base machines and local area networks will be covered. The sessions are divided into four categories -- policy changes, strategies for change, managing change, and change at DOD: adjusting to automated information systems.

In addition to the educational aspects of the conference, major data-processing and computer manufacturers will demonstrate new devices and technologies to interested spectators. The IBM Personal Computer is among the new products scheduled to be shown. Admission fees for the conference range from $75 to $295, depending on the programs selected.

The second Mid-Atlantic Computer Show, beginning Thursday from 11 a.m. to 7 p.m., is designed to attract anyone even remotely interested in computers. It will include displays of the popular electronic video games and exhibits of devices ranging in price from $150 to $250,000. According to show producers, it will encompass "100,000 square feet of display space containing over $50 million worth of equipment."

Among the major manufacturers participating are IBM, NEC, DEC, Wang, Radio Shack, Atari, Lanier, Burroughs, Qantel, Heathkit, North Star, Commodore and CPT. Virtually every one of the computer retailers in the Washington area will have a demonstration and sales booth at the show.

Since this is the International Year of the Handicapped, the latest developments in electrotechnological equipment for the disabled will be demonstrated. Devices that allow the blind to "read" regular textbooks through electronic impulses will be among the inventions showcased.

Another new machine, developed by Clayton Brokerage Co. of St. Louis, will demonstrate information-management and data-processing capabilities that enable a securities dealer to make market predictions based on analysis of past trends. Other devices to be displayed include computer-controlled talking cars and wristwatches.

The Mid-Atlantic Computer Show runs through Sunday and is expected to draw more than 35,000 people. Admission is $5 for adults and $2 for children.