Sketchpad Vector Drawing Program

Sketchpad and Ivan Sutherland

Sketchpad was the first vector-based drawing program, or 'graphical user interface,' invented by computer scientist Ivan Edward Sutherland in 1963, and was the predecessor to all modern vector drawing programs in use today. Sketchpad, also known as "Robot Draftsman," contained many cutting-edge 'object control' features that are on par with today's current technology.

Sketchpad was a hardware-based drawing program utilizing 'object oriented programming' to manipulate and control objects and "instances" in much the same way that today's CAD vector programs do.

As with most modern-day vector drawing software, Sketchpad allowed the user to draw a line between two coordinates creating an "object," then one could constrain the geometric properties of that object to pre-defined parallel and perpendicular perameters.

MIT Lincoln Laboratory's TX-2 Computer

Sketchpad relied on an interactive CRT screen and light pen to manipulate graphic objects - a system that resembles the modern Wacom Cintiq drawing tablet. Sketchpad ran on a huge Lincoln TX-2 computer developed by the MIT Lincoln Laboratory. The TX-2 computer was a transistor-based computer with a miniscule 64K 36-bit core memory. Unlike modern computer monitors which use pixels to display data, the TX-2 computer's CRT screen traced a sloid electron beam across the screen.

Amazingly, it would be over 28 years until the creation of a viable computer-based drawing program entered the commercial market, and almost 30 years until the introduction of a commercially available vector drawing program similar to Sketchpad.

Digital VAX Graphics Hardware

One of the first commercially viable vector-graphics hardware developments took place in the early 1980s, with the development of the 32-bit Digital VAX (Virtual Address eXtension) 8900 series, and VAX 9000, which were CISC computers produced by Digital Equipment Corporation in Maynard, Massachusetts. Digital Equipment was founded by two of the engineers who worked on the TX-2 project for MIT Lincoln - Ken Olsen and Harlan Anderson.

Apple Macintosh and Photoshop

Across the country in Cupertino, California, the fledgling company Apple Computer, Inc. introduced the Macintosh, which was bundled with one of its "killer applications" known as Adobe Photoshop. Unlike the vector-based programs used on the Digital VAX, Photoshop was designed exclusively for bitmap and image pixel manipulation. With the invention of Adobe Illustrator in 1986, Apple entered the 2D vector-based drawing program arena, and Digital Equipment steadily lost its market share in the graphics field.

CAD Object-Oriented Programming

On a parallel development track during the early 1980s, vector-based 3D 'computer-aided design' (CAD) programs were being developed, utilizing object-based Fortran (Formula Translating System) and OOP (object-oriented programming) computer language used in conjunction with the UNIX operating system and Digital VAX hardware.

Early CAD programs used a wire-frame model to represent a three dimensional object, but CAD software would soon be dramatically improved with the advent of 'solid modeling.' 3D modeling programs use B-rep (boundary representation), the 'geometric modeling kernel,' and NURBS (Non-uniform rational B-spline) - all of which would allow a mathematically precise, visual representation of complex free-form surfaces. By the early 1990s, Windows based PCs became the dominant platform for 3D modeling software, and Digital Equipment Corp. was sold to Compaq.