This is the Computer Science A and AB Description from College Board AP Central.
http://www.cis.fiu.edu/~downeyt/advisor/52435apcompscilocked_4315.pdf

The AP Test: Lasts 3 hours and Consists of two parts: 1 hr. 15 min. for 40 multiple choice questions and 1 hr. 45 min. for four free response. The test is entirely pencil and paper. In other words, no computers are available.

AP tests are graded on a scale of 1 to 5 with 3 considered to be passing. The test is difficult but only requires a score of 40 % to pass. A score of about 70 % will earn a grade of 5.

This is an example syllabus for the Computer Science A exam from the College Board.
http://www.cis.fiu.edu/~downeyt/advisor/ap06_compsci_a_syllabus1.pdf

This is an example syllabus for the Computer Science AB exam from the College Board.
http://www.cis.fiu.edu/~downeyt/advisor/ap06_compsci_ab_syllabus1.pdf