Sometime in 1988, the keyboard of my Sinclair ZX Spectrum 48K was finally broken beyond repair, and I asked my parents for a 128K version of the same computer. Instead, they surprised me with an Atari 520 ST. It was my first real-world experience with a graphical desktop environment, complete with windows, icons, and a mouse.
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The ST was an amazing machine, not only compared to my poor old “Speccy” and similar cheap home computers, but even to the IBM PC compatibles in my school’s comp-sci lab, which cost at least twice as much.
Decades later, I decided to learn more about the graphical desktop that ran on the Atari ST - GEM by Digital Research Inc. This post is the result of my modest research project.
Much of my source material comes from the Computer History Museum. If you enjoy the article and feel generous, please consider making a donation to the museum.
In July 1981, Lee Jay Lorenzen, a recent graduate from Southern Methodist University, began working at Xerox’s Office Products Division in Dallas, Texas1. He was hired to work on the 16-bit version of the recently released Xerox 820 personal computer (code named Worm, as it was supposed to eat Apple). Once inside Xerox, Lorenzen got access to the Xerox Star, the first commercially available computer with a graphical desktop, inspired by the legendary Xerox Alto workstation.
Impressed by the Star’s capabilities, but not its price, Lorenzen set out to design an 8086-based personal computer that would have similar user interface to the Star’s but with a more reasonable price tag. The prototype was named Lone Star, and Lorenzen made a video2 to promote it within Xerox.
In a nutshell, the Lone Star was a desktop computer based on Intel 8086 CPU, with 128 KB of RAM, 8 KB of ROM, optional 5.25” floppy drives, and running the CP-M/86 operating system. The interesting part was the graphical desktop environment, which was obviously influenced by the Xerox Star - with menus, a message bar, icons and windows. It was coded in Digital Research’s Pascal/MT+.
The Lone Star was noticed within Xerox, and Lorenzen even travelled to Palo Alto to demonstrate it to the famous PARC research group3. The follow-on to the Xerox 820 ended up being Xerox 820 16/8 - a much less ambitious machine without a graphical desktop. However, one of Lorenzen’s former managers who had moved to Digital Research Inc. (DRI) was impressed enough by his work to recruit him there.
Lee Jay Lorenzen joined DRI in January 19834 and started at the Operating Systems Department, led by Frank Holsworth. His first project was a character-oriented windowing system for Concurrent CP/M5. In August 1983, after seeing VisiCorp’s operating environment Visi On6, Lorenzen and another developer in the same team Jason Loveman decided they could do better. They came up with the first prototype of a graphical desktop environment and demonstrated it in late 1983. The prototype was developed on an Apple Lisa computer running an internal port of Concurrent CP/M for the Motorola 68000 CPU.
Lorenzen named the prototype “Crystal” - he had heard of an IBM project code name “Glass”7 and, without a doubt inspired by name games at Xerox, wanted to one-up it.
The success of the demo earned Lorenzen a transfer to the Graphics Department under Don Heiskell, creator of the GSX graphics library. Within the department, a new team was formed to develop the desktop environment. Lorenzen was the lead, and other members included Gregg Morris and Lowell Webster with Tim Oren and Andrew Muir joining later8. A separate team worked on GEM applications such as Paint, Draw and Graphing.
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By the time the project officially started, it was clear that DRI’s CP/M-86 operating system had lost the battle for the PC market and the new target platform for GEM was set to be MS-DOS. That meant not only dealing with the 640KB memory restriction9 but abandoning the multitasking for the time being.
The graphics environment was essentially ready by late 1984. It turned out the name “Crystal” was not available, so they renamed it to Gem: the most valuable crystal. Lorenzen decided to pretend it was an acronym: Graphic Environment Manager.
GEM was officially introduced at COMDEX in November 1984 and was generally well received, with two major criticisms:
Initially, GEM ran on IBM machines, but not on clones like Compaq. The restriction was lifted soon after.
GEM ran well on the top-of-the-line systems like IBM PC AT but was sluggish on less expensive and more popular 8088-based machines.
On February 23, 1985, Lee Jay Lorenzen demonstrated the desktop environment on The Computer Chronicles10.
On February 28, 1985, GEM 1.1 shipped.
In January 1984, while the GEM project was still in its early stages, Commodore’s founder and CEO Jack Tramiel suddenly left the company after a fight with chairman Irving Gould. Never one to quit, he founded Tramiel Technology Ltd. and in July grabbed the opportunity to buy Atari from Warner Communications11. Tramiel took with him a number of talented engineers from Commodore, including Shiraz Shivji, and began work on a next generation home computer. The goal was to have it ready for the January 1985 Consumer Electronics Show (CES).
The main decisions about the hardware were made before the Atari takeover: the machine would be based on Motorola’s 68000 processor with advanced graphics and built-in MIDI. For software, the team knew they wanted a modern graphical user interface with bitmap graphics. They also knew they did not have time to develop the operating system from scratch, so they contacted DRI.
All that Digital Research could demo to the Tramiel’s team at the time was Lorenzen’s Crystal prototype that ran on an Apple Lisa. They were not impressed; one of the ex-Commodore engineers called it “smoke and mirrors”. However, the only alternative was Microsoft, and they had even less to show, so the decision was made to go with DRI.
In September 1984, Atari’s software team traveled to Monterey to port the new PC version of GEM to the 68000 CPU. In the beginning, the 68000 port ran on top of CP/M-68K, but it was clear they needed a more modern OS, with a hierarchical file system. DRI’s Jason Loveman (who had originally worked with Lorenzen on the first GEM prototype) started developing a new disk operating system named GEMDOS12 specifically for that purpose.
The entire situation was pretty hectic for a while: DRI’s graphics group worked on the PC version of GEM on MS-DOS; Atari developers were porting it to Apple Lisas running CP/M-68K; and Loveman was building GEMDOS. Against all odds, they succeeded. The operating system for Atari ST consisting of GEM running on top of GEMDOS was named TOS which simply meant “the operating system”, although many believed “T” actually stood for “Tramiel”.
Atari 520 ST, soon nicknamed “Jackintosh”, was introduced at the 1985 Consumer Electronics Show in Las Vegas and became an immediate hit. GEM ran smoothly on the powerful ST’s hardware, and there were no clones to worry about. Atari developed its branch of GEM independently of Digital Research until 1993, when the Atari ST line of computers was discontinued.
By 1985, Apple’s hopes that the Macintosh would take the world by storm as the IBM PC had four years earlier proved unfounded. At the same time, efforts to bring a graphical desktop to PCs looked promising, and Apple resorted to legal action to stop them, or at least slow them down. Microsoft Windows, half-baked as it was at its first release, was an obvious target, but even before that, Apple sent its lawyers to DRI and threatened with a lawsuit. Their claim was that GEM copied Macintosh’s “look and feel”.
According to Lee Jay Lorenzen, it was Bill Gates who convinced Apple to go after DRI first:
I said, "Bill, did you do this? I heard that you sent Apple to pester Digital Research," and he owned up to it! I've always had good interactions with Bill. I know his reputation in the industry, but to me, personally, he's always been a supporter. He certainly didn't lie about it. He said, "Yes, they came over bugging me about the UI, and I said, ‘Windows is kind of like a Macintosh, but what's really like a Macintosh is GEM at Digital Research. Why don't you go hassle them for a while?’"
Lorenzen argued that he had “stolen” his design from Xerox, not Apple, but it is hard to deny that Gates had a point13. Apple’s user interface was, of course, inspired by the Xerox Alto, but the Lisa (and later the Macintosh) introduced significant innovations that GEM adopted14. Superficially, GEM did look like a color version of Macintosh, albeit it lacked some functionality and built-in applications.15
Ultimately, DRI’s leadership chose not to face Apple at court. They reached an agreement16 to modify GEM to look less like the Macintosh. The result was GEM 2.0, with two non-resizable file windows permanently on the desktop, without icons and no “trash bin”.
GEM 2.0 was released in March 1986 and Lorenzen was credited as one of the four authors. By that time, though, he had left Digital Research to cofound Ventura Software17.
Interestingly enough, Apple never went after Atari, and TOS continued to be based on GEM 1.0.
The “crippled” versions of GEM still saw some success. A very popular PC clone in Europe, the Amstrad PC 1512 used GEM as its primary desktop environment, as did Atari PC computers. But by that point it was clear that DRI did not really back its desktop environment. In a report from January 1988, Stewart Alsop II had this to say about GEM:
There are other systems that some people - primary the designers - would like to include as contenders. These include Digital Research’s Gem, which started out fairly strong but appears to have suffered from a lack of leadership. The interface is the closest to the Macintosh in structure and approach, but Digital Research has never been able to provide it with a complete or workable keyboard interface (using the home key to select an object just doesn’t make sense) nor to present enough of a marketing strategy to win over any major OEMS.
The last commercial GEM release was version 3.11, published in November 1988. The project was led by of one of the original authors, Lowell Webster18.
A few more versions were released internally or bundled with other products19. An interesting offshoot was ViewMax which served as a graphical shell for DR DOS - the most successful product of Digital Research’s final years20.
Novell acquired DRI in 1991 and sold its technologies to Caldera in 1996. Caldera eventually open-sourced GEM. According to a VCF forum discussion, three major distributions of the open-sourced GEM appeared: FreeGEM, Owen’s Free GEM and OpenGEM. Code and binaries for all three can still be found online, but development ended by the late 2000s.
Sadly, GEM remains only as a part of computing history.
Several articles about GEM mention that it was developed by a former Xerox PARC employee. It is pretty clear that Lorenzen never worked at PARC; he was employed by Xerox Office Products Division in Dallas, Texas.
Visi On was released in December 1983 but was first demonstrated a year earlier, so it is not clear when Lorenzen first saw it.
The GEM 1.1 Desktop Info dialog lists six authors: Lee Jay Lorenzen, Gregg Morris, Lowell Webster, Tim Oren, Andrew Muir, and Jim Bourne
To work around the memory limits, GEM used something Lorenzen calls “set-aside” mode: when an application launched, the desktop environment unloaded from memory and reloaded after the application exited.
A chapter from the book PROFESSIONAL GEM by Tim Oren contains some history of GEM development, including the Atari port.
A presentation by Jason Perkins at Vintage Computer Festival East 2020 where he compares the UIs of Xerox Star and Apple Lisa is available on YouTube.
The New York Times article Digital Research To Modify GEM published on October 1, 1985, quotes Judy Mervis of Digital Research stating that DRI agreed to make GEM “less similar in operation and appearance to Apple's programs that run on Mcintosh”.
Ventura Software produced the popular desktop publishing software Ventura Publisher that was initially based on GEM, with DRI’s permission. Interestingly, it was distributed by Xerox.
A short video interview with Lowell Webster can be found at Computer History Museum website. It seems it was filmed during a Digital Research reunion.