Turbo Pascal

Turbo Pascal was a special set of tools for making programs on older computers. It had everything a programmer needed to write code and turn it into working software. It used a language called Pascal and worked on early operating systems like MS-DOS.

It was made by a company called Borland, and one of its creators was Anders Hejlsberg. Turbo Pascal was special because it could quickly turn written code into ready-to-use programs. This speed made it very popular among people who wrote software for PCs.

Later, Borland made more advanced versions called Borland Pascal for professional programmers. These versions had extra tools to help build bigger and better software. Today, some of the old versions of Turbo Pascal can be downloaded for free because they are important pieces of history in the world of computer programming.

History

Philippe Kahn saw a chance for his new company, Borland, to create special tools for programmers. Programmers usually wrote code using a text editor, then compiled it into object code, and linked it with other files to make a program. This took many steps and a lot of time.

Kahn wanted to make a tool that did all these steps quickly and easily. He sold this tool, Turbo Pascal, for just US$49.95, which was very cheap at the time. The Turbo Pascal compiler was created by Anders Hejlsberg and included a special interface and editor. It was first released in 1983 for CP/M, CP/M-86, and DOS machines. Turbo Pascal was popular because it compiled programs very quickly and was easy to use. Unlike other tools, Turbo Pascal did not have copy protection and could be used freely on different computers.

The tool was well-received, with many people liking its speed, price, and ease of use. It became very popular among programmers. Later, Borland replaced Turbo Pascal with Borland Delphi, which could run old Turbo Pascal programs. In 2006, Borland brought back the Turbo name for new tools, but these were discontinued in 2009. Other companies also made tools that worked with Turbo Pascal, like Free Pascal and Virtual Pascal.

Features

Turbo Pascal let programmers add special code called assembly language into their programs from version 6. This gave them more control over the computer.

The programming tools helped find and fix mistakes. Users could see and change values while the program ran and set stops to pause the program. Later versions let programmers look at assembly language code step by step. Extra tools were made by Turbopower Software for more advanced needs.

Turbo Pascal also let programmers split big programs into separate parts called units. This made big projects easier to manage and reuse code. For example, uses crt; would include functions from another part of the program.

From version 5.5, Turbo Pascal added features for object-oriented programming, like classes and inheritance. This helped programmers create reusable code and build more complex programs.

Some versions of Turbo Pascal did not work well on very fast computers because of a part called the CRT unit. This could cause errors on processors faster than about 200 MHz. But there were ways to fix this, like using special patches or changing the program.

Versions

CP/M and DOS versions

Version 1

Version 1 came out on 20 November 1983. It was a simple system that worked in memory and made program files for DOS and CP/M computers. It could also make programs for CP/M-86 computers. The program files had size limits to keep things simple.

It worked on DOS, CP/M, or CP/M-86 computers with 64 KB of memory and one floppy disk. The CP/M version ran on many machines with Z80 processors, or an Apple II with a Z80 card. The DOS and CP/M-86 versions ran on many Intel 8086 and Intel 8088 machines, including the IBM PC. Everything needed to run the program, including a simple spreadsheet called MicroCalc, could fit on one floppy disk.

The way the program looked and worked was advanced for its time. It ran well and compiled quickly even with the limited memory of home computers. The way you used the program was simple and easy, with clear menus. Early versions used keys like on WordStar, which was common then. Later versions could show explanations of programming words when you pointed at them and pressed a key.

Besides normal programs, the compiler could also make small tools that stayed in memory, letting the computer do other tasks at the same time. Borland made a small set of tools called Sidekick that let users keep a diary, notes, and more.

Version 2

Version 2 came out on 17 April 1984. It improved on the original Turbo Pascal. It added a way to swap extra pieces of programs from the disk into memory when needed. It also added ways to manage memory better and work with new computer features.

Version 3

Version 3 was released on 17 September 1986. It added support for special graphics and different ways to handle numbers in programs.

DOS versions

Version 4

Version 4 was released on 20 November 1987. It was completely rewritten. It made programs in a new format and dropped support for older CP/M systems. It added new features like separate parts of programs and a better way to use the screen.

Version 5.0

Version 5.0 came out on 24 August 1988. It changed the default color of the program to blue and added ways to stop and watch parts of programs while they run.

Version 5.5

Version 5.5 was released on 2 May 1989. It added features for a new way of organizing programs, including ideas like classes and inheritance. It also added better help and ways to copy pieces of code.

Version 6.0

Version 6.0 was released on 23 October 1990. It added ways to mix computer code directly into programs, support for a new set of tools, mouse use, and ways to work with many documents at once.

Version 7.0

Version 7.0 came out on 27 October 1992. It added support for making programs for DOS, Windows, and special Windows files. It also added colors to show different parts of the program.

Turbo Pascal for Windows

Two versions called "Turbo Pascal for Windows" were made for Windows 3.x: TPW 1.0 and 1.5. They were later replaced by Borland Pascal 7, which also worked with Windows. These versions made programs that worked with Windows and had a Windows-style way to use them.

Turbo Pascal for Macintosh

Borland made Turbo Pascal for Macintosh in 1986. It worked well but did not have good tools to find and fix problems. Support for Macintosh was stopped soon after.

Freeware releases

Borland later made several versions of Turbo Pascal available for free after they were no longer updated. These include versions 1.0, 3.02, 5.5, and Turbo Pascal 7.01. Most of these are still available to download.