CHICAGO (AP) _ Each year in more than 200 booths at the Council for Exceptional Children's annual convention, the special education business displays its wares: from $2,800 motorized wheelchairs to a $38 jack-in-the-box with a motorized crank that physically impaired children find easy.

In the dozen years since the federal Education for All Handicapped Children Act guaranteed disabled children ''a free appropriate education,'' publishers, toymakers, wheelchair manufacturers, hearing aid makers and others have rushed to fill the resulting market.

Education marketing consultants estimate that schools spend roughly twice as much on materials and supplies for handicapped youngsters as for regular students, and many times more in the case of the severely handicapped.

The number of publishers producing special education materials has grown from about 20 in 1977 to more than 300 in 1986, according to Victor E. Fuchs, president of Linc Resources Inc. of Columbus, Ohio, an education marketing company.

Fuchs estimates there is an $80-100 million market for special education texts and other published materials - roughly one-tenth of the entire kindergarten-12th grade publishing market.

Some 300,000 microcomputers are being used for special education instruction - roughly one terminal per 14 handicapped pupils, estimates Charles Blaschke, president of Education Turnkey Systems Inc., a Fairfax, Va., marketing research firm.

In regular education, about 30 students share each computer on average.

Numerous enterprises have sprung up to meet the growing educational needs of disabled youngsters.

Gould Athletic Supply Co. of Milwaukee specializes in athletic equipment for the handicapped, such as basketball hoops designed to accomodate wheelchair-bound players.

Toys for Special Children, a 6-year-old non-profit foundation in Hastings- on-Hudson, N.Y., takes ordinary toys like a jack-in-the-box and equips them with special switches that make it possible for the handicapped to use them.

''It's all about controlling a part of the environment. A child's confidence increases dramatically,'' said spokesman Michael Garb.

The Feelings Factory, a small company in Raleigh, N.C., makes puppets and face stickers meant to help impaired children express their emotions. Each doll, $70 for a male-female pair, has interchangeable faces with different emotions. And the faces come in various racial hues.

A magazine for parents of disabled children, ''The Exceptional Parent,'' whose topics include, for example, choosing clothes for handicapped children, now has a circulation of 22,000.

Janus Book Publishers of Haywood, Calif., puts out softcover texts on such ''life skills'' as reading newspapers, using the phone book and finding a doctor, as well as more standard academic fare in reading, math, science and home economics.

Scholastic Testing Service, Bensenville, Ill., produces some of the many diagnostic tests for disabled children.

Phonic Ear Inc. of Mill Valley, Calif., makes systems that allow teachers to send signals directly to deaf students while shutting out distracting background noise.

Larger firms have moved into special education, too.

Walt Disney Educational Media Co. of Burbank, Calif., for example, has many filmstrips aimed at the handicapped and next fall will introduce a 20-minute Disney film featuring puppet-like characters called ''The Kids on the Block'' who simulate disabled or injured children.

Major trends on the horizon, according to Blaschke: a sales spurt for products like voice synthesizers that help the severely handicapped to communicate, and a cooling of school computer sales now that educators feel that the mildly handicapped have enough terminals.