The Computer History Museum, with permission from Adobe Systems Inc., has released the 1990 version of Adobe Photoshop free to the public for non-commercial use. All of the code is available in the imaging and editing software, with the exception of the library of the MacApp application that was licensed from Apple.
There are 128,000 lines of well-structured code contained within the 179 zipped folder and mostly written in the computer language code Pascal. This original version of Photoshop was written in an estimated 75 percent Pascal and 15 percent in the language 68000 assembler. Photoshop 1.0.1 was developed to run on the Apple Macintosh, which ran Apple Pascal on a Motorola 68000 microprocessor.
Software architect and Chief Scientist for Software Engineering at IBM Research Almaden Grady Booch compared the current version of Photoshop to the primary version and shared his views. He is also a trustee of the museum and took an in-depth look at the fundamental code structures of both softwares. He found that the base structure still exists in a more evolved format in the modern version of Photoshop. The first version includes the tiles, filters and abstractions required for virtual memory.
"Architecturally, this is a very well-structured system. There's a consistent separation of interface and abstraction, and the design decisions made to componentize those abstractions — with generally one major type for each combination of interface and implementation — were easy to follow," said Booch on the Computer History Museum's official blog.
Photoshop was designed and written by two brothers, Thomas and John Knoll during the 1980s. While attending the University of Michigan in 1987 as a PhD student, Thomas Knoll wrote a program that could display and modify digital images. His brother John used it to edit photos while he worked for a company that produced visual effects for movies. "We developed it originally for our own personal use ... it was a lot a fun to do," said Thomas on the blog.
As the program progressed, they named it "Display" and in 1988 they saw its potential to become marketable. They renamed it Photoshop, found a distributor and made 200 copies. Adobe purchased the license to distribute an enhanced version of Photoshop in 1989 and released version 1.0 in 1990. You can download the Adobe Photoshop version 1.0.1 here.
