40 years of Turbo Pascal

It is 40 years since Turbo Pascal revolutionized the coding marketplace with a slick (for the time) Integrated Development Environment (IDE) and performance to spare. So why aren’t we all using it today?

Turbo Pascal was released in 1983 and represented a shift from the traditional way programming tools worked in the early days of IBM PC compatibles. Rather than multiple compiler and linking passes that required time-consuming floppy disk access, Turbo Pascal did everything in RAM, making it considerably faster – hence the name “Turbo.”

Anders Hejlsberg, who would later go on to join Microsoft as part of the C# project, is widely credited as creator of the language, with Borland boss Philippe Kahn identifying the need for the all-in-one tool.

It was also cheap – where the competition could cost hundreds of dollars, Turbo Pascal retailed for $49.99. However, its maker, Borland, wanted a little extra if a customer planned to distribute the binaries.

Version 1 had limitations. Source code files, for example, were limited to 64 KB. It would only produce .COM executable files for DOS and CP/M – although other architectures and operating systems were supported. It would also run from a single floppy disk, saving users from endless swapping in a world where single drives were the norm and a hard disk seemed impossibly exotic – and expensive.

Version 2 came a few months later, with some minor modifications, and was followed by version 3 in 1986. However, it was with version 4, in 1987, that Turbo Pascal changed dramatically. For one, support for CP/M and CP/M-86 was dropped, and the compiler would generate .EXE executables under DOS, lifting the .COM restrictions.

Version 4 also introduced a full-screen text user interface with pull-down menus, and 1988’s version 5 gave us the familiar default blue background for the editor. For this writer, 1989’s version 5.5 was peak Turbo Pascal. Object-oriented programming features turned up, including classes and inheritance, and a step-by-step debugger.

Version 6 and 7 brought in inline assembly and support for the creation of Windows executables and DLLs respectively, but version 7 also marked the end of the line as far as Borland was concerned. Turbo Pascal for Windows would turn up, but was eventually superseded by Delphi.

However, the steamroller of tools such as Visual Basic 3 ensured that Borland never had the same success in Windows that it enjoyed under DOS.

As for Turbo Pascal, several versions were eventually released by Borland as freeware including version 1 for DOS, 5.5, and 7.

The language might have offended Pascal purists and the IDE seems a little clunky nowadays when compared to modern tools. However, 40 years ago it prompted a new era of development, one whose influence can still be felt today. ®

Source: www.theregister.com