Thursday, April 24, 2008

Legendary Turbo Pascal Compiler

Do you still remember the time?

Recently Borland stock price down to bottom as USD 1 plus.

Borland share price
Borland share price goes down.

Borland was co-founded by American technology entrepreneur Philippe Kahn in 1983 (or 1982?). Borland was once a top 10 software company in the 80s, famous for its compiler tools, most remarkable is Turbo Pascal compiler. Borland once change their name to Inprise but later change back to Borland. Philippe Kahn left Borland in 1995.

Turbo Pascal from Borland is one of the easy to use and fastest pascal compiler available on PC during the 80s. Turbo Pascal is an IDE (Integrated Development Environment, integrate editor, compiler and linker together) compiler, even though running on DOS as text base program, it was a break through, because its performance is fantastic even running on a 4.77Mhz IBM PC. While other compiler software was selling as USD one thousand to two thousand, Turbo Pascal was selling for only USD49.99 when it first release in 1984. Very quickly the software was sold over million of copies

Why Turbo Pascal can perform so well (especially on old 4.77Mhz IBM PC)?

1. It is small. As for Turbo Pascal version 5.5, the IDE and the compiler is about 200k to 300k. Software at that time is all very small in size.

2. Everything was done in memory. Normally before the program can be executed, it will be compile into an object (normally .o file), store on the disk. Then it will be link as executable file, before it can be executed and show the program result. Turbo Pascal compile and generated the executable code all in Ram, and didn't need to access to auxiliary storage (5.25" floppy disk), so it is very fast.

3. Optimized compiler core. Turbo Pascal creator Anders Hejlsberg, have spent a lot of effort in optimizing the compiler core. The compiler was written so well that it was still being used in the first three version of the later Delphi compiler.

Borland has release the earlier version of Turbo Pascal as free for use, you download from here.

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