The Apple Macintosh combined brilliant design in hardware and in software. The drawing program MacPaint, which was released with the computer in January of 1984, was an example of that brilliance both in what it did, and in how it was implemented.
For those who want to see how it worked "e;under the hood"e;, we are pleased, with the permission of Apple Inc., to make available the original program source code of MacPaint and the underlying QuickDraw graphics library.
MacPaint is the drawing program application which interacts with the user, interprets mouse and keyboard requests, and decides what is to be drawn where. The high-level logic is written in Apple Pascal, packaged in a single file with 5,822 lines. There are an additional 3,583 lines of code in assembler language for the underlying Motorola 68000 microprocessor, which implement routines needing high performance and some interfaces to the operating system.