Apple’s MacPaint and QuickDraw source code released to the world

Who here remembers MacPaint? MacPaint shipped with the original Apple Macintosh computer in 1984. It quietly shook the world in its own ways. While it was not the first bitmap graphics programs, it introduced the tool palette that can still be seen in programs like Adobe Photoshop, GIMP, and GraphicConverter.

Bitmap graphics programs made it possible to directly make pictures with a computer and mouse; previously, graphics had to be created through programming, or via keyboard interaction. (The very first may have been the Markup program that ran on the Xerox Alto computers produced in 1973.) They are called bitmap programs, as they will paint in exactly the way the user moves the mouse. The problem with bitmaps is that when you magnify the image, they look jagged, or “pixelated.” The solution is to use a vector-based drawing application, in which you create scalable, resizable objects rather than just coloring pixels. MacDraw and Adobe Illustrator are examples of this type of program.

Anyway, Apple Inc. has released the source code of MacPaint and the underlying QuickDraw software to the Computer History Museum. Programmers in the audience can dig into the source code, assuming you can work with Pascal or 68000 processor assembly.

According to the museum:

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 “under the hood”, 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.

While I enjoyed Bill Budge’s MousePaint (and RasterBlaster!) for the Apple ][, and later MacPaint and its many clones and knock-offs, I’ll leave the source code to someone who can actually use it. Either way, thanks to genius programmer and early Mac guru Bill Atkinson for helping change the world.


Author: Jason Haas

Jason is an elected member of the Milwaukee County Board of Supervisors, occasionally moonlights as an amateur gardener, and is a proud father of two, or three, depending on how you do the math.