Byte sized languages: Pascal
David Briddock explains why Pascal influenced many other languages
Pascal was developed by Niklaus Wirth in the late 1960s and named after the French mathematician and philosopher Blaise Pascal. From the outset, a key aim was to devise a language (goo.gl/LAKZd) suitable for teaching students the art of structured programming, and it soon became an integral part of the computer science curriculum.
With so many students using the language, its popularity rose rapidly. Pascal-coded applications, systems and games started to appear everywhere. Apple offered Pascal on its Apple II, Apple III and Apple Lisa computers, and some early Macintosh code was written in Pascal.
At a time when mainframe computers were simply far too expensive and inflexible for mass adoption, Digital Equipment Corporation’s very successful range of PDP and later DEC VAX computers did much to popularise the Pascal language within the business and commerce world.
The introduction of Borland’s Turbo Pascal, a very affordable product aimed at the PC marketplace, increased Pascal’s upward momentum still further. An object-oriented offering called Object Pascal appeared a little later and led to the very successful Borland Delphi product in 1985. Delphi tempted developers with a Rapid Application Development (RAD) environment, something greatly appreciated by programmers working on graphical user interface (GUI) applications.
One of Pascal’s key features is that its compiler outputs something called P-code, as opposed to the more usual machine code. By using a small machine-specific program that interprets and executes the P-code, this ‘virtual machine’ output will run on any computing platform or operating system
P-code compilation was a revolutionary idea. It freed the developer from having to rewrite the code every time a new platform or operating system was introduced - an extremely frequent occurrence in the 1980s and 1990s.
Pascal’s innovative concepts influenced many language creators. It led directly to languages such as Modula-2 and had a pivotal influence on the design for Java, which has its own version of the P-code concept - namely the platform-neutral bytecode, the Java Virtual Machine (JVM).
Pascal has lost its premier position in the academic teaching curriculum. Today’s students are far more likely to be fed a programming diet of Java or C#.NET.
Things aren’t much better outside of academia. These days Pascal is rarely used in commercial environments, so the experienced Pascal developer is presented with a very slim set of employment opportunities.
The future of Pascal seems bleak. While colleges and universities used the language as part of the syllabus, it retained a certain presence and relevance.
The open-source Free Pascal, available on Linux and many other platforms, does offer some hope for Pascal aficionados. However, without a presence in education establishments and the commercial world, it’s on a downward spiral.
So the time for Pascal seems to have passed. Nevertheless, it’s certainly secured its place in programming history and some of our most popular languages owe a lot to its existence.