may be freely moved from one computer location to another, so long as there is no possibility of it being used at one location while it's being used at another." CP/M and DOS versions
Turbo Pascal came with the famous "Book License": "You must treat this software just like a book. Instead of selling the kit through established sales channels (retailers or resellers), his new tool would be sold inexpensively via mail-order.Īs an added selling point against the bigger vendors, Turbo Pascal disks had no copy protection. Kahn's idea was to package all these functions in an integrated programming toolkit, have it run with much better performance, and charge one low price for it all. Vendors of software development tools aimed their products at professional developers, and the price for these basic tools plus ancillary tools like profilers ran into the hundreds of dollars. This process was the cumbersome product of the extremely limited resources of the early IBM PC models. For example, the Microsoft Pascal system consisted of two compiler passes and a final linking pass (which could take minutes on systems with only floppy disks for secondary storage). In the early IBM PC market (1981–83) the major programming tool vendors all made compilers that worked in a similar fashion.
Programmers wrote source code and entered it using a text editor, a compiler then created object code from source (often requiring multiple passes), and a linker combined object code with runtime libraries to produce an executable program. Historically, the vast majority of programmers saw their workflow in terms of the edit/compile/link cycle, with separate tools dedicated to each task. Philippe Kahn first saw an opportunity for Borland, his newly formed software company, in the field of programming tools.