Turbo Pascal |
Turbo Pascal, is a Compiler and a powerful Integrated Development Environment (IDE) for the Pascal programming language running mainly on MS-DOS, developed by Borland. The name Borland Pascal was generally reserved for the high end packages (with more libraries and standard library source code) whilst the original cheap and widely known version was sold as Turbo Pascal. The name Borland Pascal is also used more generically for Borland s dialect of Pascal.
=History=
Turbo Pascal was based on the Blue Label Pascal compiler originally produced for the NasSys cassette-based operating system of the Nascom microcomputer in 1981 by Anders Hejlsberg. This was first rewritten as the Compass Pascal compiler for the CP/M operating system and then as the Turbo Pascal compiler for DOS and CP/M. A version of Turbo Pascal was available for the Apple Macintosh from about 1986 but was eventually discontinued around 1992.
==Version 1.0==
See also [http://community.borland.com/article/0,1410,20693,00.html Antique Software: Turbo Pascal v1.0]. Borland licensed the Pascal compiler core, written by Anders Hejlsberg (Poly Data was the name of his company in Denmark), and added the user interface and editor. Anders joined the company as an employee and was the architect for all versions of the Turbo Pascal compiler and the first three versions of Borland Delphi.
When the first version of Turbo Pascal appeared on November 20 1983, the type of IDE which it used was relatively new. On its debut in the United States market, Turbo Pascal retailed for United States dollar49.99. The integrated Pascal compiler also was of very good quality compared to other Pascal products and was affordable above all. The Turbo name alluded to its compilation speed as well as the speed of the executables it produced. The speed of these com executable files was a revelation for developers whose only previous experience programming the PC was with Microsoft s BASIC.
The IDE was incredible for its day. It was simple and intuitive. It had a menu system that was well organized. Early versions used the WordStar control key layout. Later versions of the IDE had the ability to instantly look up the definitions of the keywords of the language just by putting the cursor over a keyword and hitting the help button. The definitions also frequently included example code that used the keyword. This enabled the inexperienced programmer to learn Pascal simply by using the IDE, without actually requiring help from a book.
It had the ability to easily integrate assembly language within Pascal. The user could single step through a program quite easily, and when they got to an assembler block, they could single step through that too. All the while the user could add watches on variables and registers quite easily in a well placed window in the IDE. Even programs using IBM PC compatible graphics mode would flip to graphics mode then flip back to text mode while they were single stepping. With a single keypress, they could flip back and forth to graphics mode at will.
On top of all this, it included a code profiler that could report on which parts of the program were using the most time. The books included with Borland Pascal had detailed descriptions of the Intel assembler language, going so far as to provide the clock cycles required of each instruction. Overall this system, as a whole, made for a relatively pleasant experience when trying to optimize code; the user never had to leave the IDE. This all worked out of the box and was put together so simply that a high school student could use it.
In the early 1990s, it was used in several universities to teach the fundamental concepts of programming. Even though it is obsolete, it is still taught at secondary, sixth form level and University level in the island of Malta.
==Competition with Microsoft Pascal==
It is likely that Microsoft Pascal was dropped because of the competition provided by Turbo Pascal s good quality and low price. Another theory is that Borland made an agreement with Microsoft to drop development of Turbo BASIC programming language, a BASIC IDE that stems from Turbo Pascal, if Microsoft would stop developing Microsoft Pascal. For a while, Microsoft produced QuickPascal, which was almost 100% compatible with Turbo Pascal.
==5.5+ Object Pascal==
Over the years Borland enhanced not only the IDE but also the programming language. From version 5.5 onwards some object oriented programming features were introduced. Some people call these extensions Object Pascal although that is more commonly used as a name for the language underlying Delphi programming language (which has two totally separate OOP systems). The last version released was version 7. Borland Pascal 7 contained an IDE and compilers for creating DOS, DOS extender and Windows 3.x programs. Turbo Pascal 7 on the other hand could only create standard DOS programs.
==Successors==
By 1995, Borland had dropped Turbo Pascal and replaced it with the Rapid Application Development environment Delphi, which included the language Object Pascal. Native 32-bit Delphi versions still support the more portable Pascal enhancements (read: that are not 16-bit centric) of the earlier products including the earlier static object model.
=See also=
=External links=
*[http://community.borland.com/museum/ Borland Developer Network Museum] *[http://community.borland.com/article/0,1410,20803,00.html Antique Software: Turbo Pascal version 5.5] *[http://www.merlyn.demon.co.uk/clpb-faq.txt comp.lang.pascal.borland FAQ] *[http://www.devq.net/pascal/ Turbo Pascal Programmers Page] *[http://www.programmersheaven.com/zone24/cat32/3916.htm Turbo Pascal Reference], an electronic freeware book in text format.|
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