puter system. In 1971 one computer system had a Pascal compiler. By 1974 the number had grown to 10 and in 1979 there were more than 80. Pascal is always available on those ubiquitous breeds of computer systems: personal computers andl professional workstations. Questions arising out of the Southampton Symposium on Pascal in 1977 [Reference 10] began the first organized effort to write an officially sanctioned, international Pascal Standard. Participants sought to consolidate the list of questions that naturally arose when people tried to implement Pascal compilers using definitions found in the Pascal User Manual and Report. That effort culminated in the ISO 7185 Pascal Standard [Reference 11] which officially defines Pascal and necessitated the revision of this book. We have chosen to modify the User Manual and the Report with respect to the Standard - not to make this book a substitute for the Standard. As a result this book retains much of its readability and elegance which, we believe, set it apart from the Standard. We updated the syntactic notation to Niklaus Wirth's EBNF and improved the style of programs in the User Manual. For the convenience of readers familiar with previous editions of this book, we have included Appendix E which summarizes the changes necessitated by the Standard.

, A preliminary version o~ the programming language Pascal was dra~ted in 1968. It ~ollowed in its spirit the A1gol-6m and Algo1-W 1ine o~ 1anguages. A~ter an extensive deve10pment phase, a~irst compiler became operational in 197m, and pub1ication ~ollowed a year 1ater (see Re~erences 1 and 8, p.1m4). The growing interest in the deve10pment of compilers ~or other computers ca11ed ~or a conso1idation o~ Pascal, and two years of experience in the use o~ the 1anguage dictated a few revisions. This 1ed in 1973 to the pub1ication o~ a Revised Report and a de~inition o~ a 1anguage representation in terms of the ISO cha:.:.acter set. This booklet consists o~ two parts: The User Manual, and the Revised Report. The ManUAl is directed to those who have previous1y acquired some ~ami1iarity with computer programming, and who wish to get acquainted with the 1anguage Pascal. Hence, the style o~ the Manual is that o~ a tutorial, and many examp1e~ are inc1uded to demonstrate the various ~eatures o~ Pascal. Summarising tab1es and syntax speci~ications are added as Appendices. The Report is inc1uded in this booklet to serve as a concise, u1timate reference ~or both programmers and imp1ementors. It defines stAndArd Pascal which constitutes a common base between various implementations of the 1anguage.