The titular house in Mystery House

The titular house in Mystery House

Mystery House and Sierra On-Line - Getting Graphic

Sierra On-Line 1980

Let there be graphics

Roberta and Ken Williams, founds of computer video game company On-Line Systems, later to be called Sierra

1981 image of Roberta and Ken Williams, founders of On-Line Systems, later known as Sierra


Plain text doesn’t placate computer adventure gamers for long. In 1979, Roberta Williams is a housewife with two kids, living in Simi Valley, California. Her husband Ken is a programmer at Informatics in Los Angeles, working on large mainframe computers. One evening, working at home on a terminal hooked up to the computer at work, Ken fires up Crowther and Woods’ Adventure aka Colossal Cave game and shows it to Roberta. She is instantly hooked, obsessively playing the game to its conclusion. Ken subsequently purchases an Apple II computer, but Roberta isn’t very impressed with the few Scott Adams text adventures she buys for it. Looking for a real challenge, she writes her own adventure game, and she and Ken decide to try something completely new by adding graphics to it. Mystery House, on 48K diskette for the Apple II, becomes the first computer adventure game to combine text with graphics. In a tale inspired by Agatha Christie’s And Then There Were None, as well as Parker Brothers’ mystery board game ClueI, the player must roam a house finding treasure and avoiding the deadly fates of the other occupants. User input is a limited verb-noun parser with a vocabulary of a paltry 300-400 words… well below the over 600 word library available in Infocom adventure games like Zork. However, Mystery House does contain 70 images, rough outlines created by Roberta on a VersaWriter tablet using a metal arm with an electronic eye at the tip. With this arm, an image drawn on paper can be traced, and Ken writes a program to convert the drawings into plotting commands that the computer will execute, drawing the illustrations without having to take up too much memory space. He also invents a special language to create the game, for use only in making graphic adventure games, called the Sierra Creative Interpreter. SCI takes the same route as competitor Infocom’s ZIL; it is a platform agnostic language that can be easily adapted to any computer.

They launch their new company, On-Line Systems, along with Mystery House and two other programs called Skeetshoot and Trapshoot, with an ad in the pages of the May, 1980 issue of Micro magazine. Despite the rudimentary artwork, Mystery House is a sensation upon release. Priced at $24.95, the Williams sell 11,000 copies of the game inside the first year, grossing nearly 300,000 dollars for the new company.

Snap of Mystery House, a graphic adventure game by On-Line Systems 1980

The sketchy graphics of Mystery House


 On a Quest

That same year, looking for more bucolic surroundings to raise their two young boys, the Williams family pick up stakes and move from the LA area to Coarsegold, CA.; a brief 40 minute or so ride north from there and you’re into Yosemite National Park. They produce 20 more games for the Apple II, including further “Hi-Res” adventures Mission Asteroid, based on SF novel Lucifer’s Hammer, by Larry Niven and Jerry Pournelle.  The first colour adventure game, Wizard and the Princess comes from Roberta’s love of fairy tales and Ulysses and the Golden Fleece is taken from Greek mythology. Produced by Roberta over a span of six months, Sierra also releases Time Zone in 1982, sporting over 1300 colour images and packed onto both sides of an astounding six floppies. Referred to in ad copy as a “micro-epic”, the game is a response to the feeling of disappointment Roberta always experiences at having a well-made adventure game come to an end: the length of Time Zone ensures that players won’t get that feeling of finality any time soon. That same year, the company name is changed to Sierra On-Line.

Ad for Time Zone, a computer video game by Roberta Williams and On-Line (Sierra)

A suitably epic 1981 ad for the epic Time Zone


Feedback on the Williams’ work rolls in from the likes of Apple co-founder Steve Wozniak, who extolls the benefits of entertainment programs like those from Sierra for the increasingly popular home computer. To ease the process of programming the company’s contributions to the gaming landscape, two graphic utilities, called Paddle Graphics and Tablet Graphics, are developed to automate the illustrations in the games. In 1983, IBM asks Sierra to produce a game to show off the graphical capabilities of a new computer they are skewing towards the gaming market, then known only by its codename: Peanut. So feared is the idea of IBM entering the low-end computer market, that Apple’s stock price is halved overnight just on the rumour of such a machine. Using a provided prototype system, Roberta designs the next evolution of the graphical adventure. With Williams writing the story, artists then illustrate the scenes which are traced on a Calcomp Graphics Tablet. The result is an animated adventure game in astounding 16-colour CGA psuedo-3D graphics, allowing the player’s onscreen alter-ego to walk in and around 80 different locations. The process is actually similar to that of the original Mystery House: the tablet merely gives the computer the instructions of what to draw, which it does in real-time as the player moves to different “rooms” in the game. The computer takes about four seconds to draw and colour each scene, although the drawing process itself is strangely compelling to behold: it’s like watching a small child with extraordinarily fast fingers completing a fantasy-themed colouring book.

Ported to more popular systems like the Apple II family and the IBM PC, King’s Quest sells over 2.7 million copies, and is followed by eight sequels.


With a team of seven programmers and artists and a development cost of $700,000, King’s Quest is released in 1984, for what is now known as the IBM PCjr. Players control Sir Graham , who is charged by King Edward to search the kingdom of Daventry for three treasures. The PCjr ends up tanking in spectacular fashion, felled mostly because of its atrocious keyboard: wireless, but with rubber chiclet-style keys that make using it a chore. An update to the computer in the later part of 1984 fixes the keyboard problem, but the damage has been done. IBM only manages to move about 300,000 units all told, and mercifully puts Jr to sleep by ending production in April of 1985. Sierra, on the other hand, has a major hit on their hands. Ported to more popular systems like the Apple II family and the IBM PC, King’s Quest sells over 2.7 million copies, and is followed by eight sequels.

Greetings From Andromeda

In 1986, early Sierra employees Scott Murphy and Mark Crowe, aka The Two Guys from Andromeda, are coming off a rough assignment, working on Sierra’s adventure game adaptation of the Disney film The Black Cauldron. They approach Ken Williams with the idea of creating a humorous science-fiction adventure game. Unconvinced of the commercial viability of the project, Williams says no. But they go ahead and develop a four room game around the premise during their spare time, and when Williams sees the demo he gives Murphy and Crow the okay to procede. Released that year, Space Quest is another huge hit for Sierra, and it spawns six follow-ups. Packed full of SF references on everything from Douglas Adams’ book series The Hitchhiker’s Guide To the Galaxy to actual alien crash sites, the series follows the exploits of space janitor Roger Wilco. This cosmic custodial engineer has an uncanny ability to stumble into, and then unravel, the galaxy domination plans of arch-villian Vorhaul Sludge (who makes his first physical appearance in the second instalment). Space Quest 7 is announced, complete with a trailer, for 1998, but it is eventually cancelled by Sierra. Incensed by Sierra’s abandonment of one of computer gaming’s most beloved characters, fans create the Save Space Quest 7 webpage to attempt to gain Wilco a reprieve.


Cover for Softporn Adventure, a computer game by On-Line systems

They’re soaking in it, on the cover of Softporn Adventure: L to R: Diane Siegal, On-Line production manager, Susan Davis, bookkeeper, Roberta Williams, author of Mystery House, 1981


Shady Characters

1987 sees release of the controversial Leisure Suit Larry, by Al Lowe. Based on a 1982 text-only adventure game called Softporn by Chuck Benson (Gary Thompson later develops his own improved version of the program) , the goal of the game is to get the sleazy title character into bed with three different women. The game is a particular hit with bored male office workers, and it introduces the “Boss” key, which instantly clears the screen of any evidence of the game in case the manager walks by. Of course, many sequels ensue.

With Larry and other additions to the Quest series of games including Police Quest, created by real-life LAPD detective Jim Walls, Sierra retains its lock on the graphic adventure market until challenged by George Lucas’ Lucasfilm computer games division (later re-named LucasArts), with the 1987 release of their first in-house produced game, the graphic adventure Maniac Mansion. Along with their Monkey Island series and the Indiana Jones graphic adventures, LucasArts adventure games eshew the verb-noun command parser for a slick point-and-click user interface. While Sierra succeeds in revamping their games to take advantage of this new technique, they lose their near-monopoly on the graphic adventure market.

JUMP: Video playlist of Sierra adventure games

A screenshot from The ImagiNation Network Revival, an emulated version of Sierra's online service 1991

The ImagiNation Network Revival



Heading into the 90′s, Ken Williams’ thoughts turn to his aging grandmother. Looking to provide her with activities and games she can access without leaving home, he devises The Constant Companion. It is to be an online service for seniors that would provide games like bridge and backgammon, accessible any time they like through phone lines via an easy to understand graphical user interface (GUI). Launched in 1991 as The Sierra Network, the visionary system quickly expands beyond seniors and parlour games, with arial dogfighting game Red Baron, turn-based RPG The Shadow of Yserbius,, and a Leisure Suit Larry-themed casino area called Larry Land soon added. Its quickly expanding scope causes Williams to sell half of the system to AT&T, who rename it The ImagiNation Network (INN). AT&T ends up muscling Sierra out completely amid a morass of bureaucracy, opting to develop their own games for the service, whereby membership starts to dwindle.  AT&T ends up selling INN to America On-Line, who shutter the system in 1996.

A Dark End

Roberta Williams sheds her squeaky-clean fairy-tale image with the extremely dark Phantasmagoria, a point-and-click CD-ROM horror adventure game released in 1995 to great success.  It is followed by the less successful Phantasmagoria: A Puzzle of Flesh the next year, made without Williams’ involvement.  Ken and Roberta leave the company in 1996 after its sale to CUC International.  After a byzantine series of mergers, splits and acquisitions, Sierra ends up acquired by video game giant Activision in 2008, who then shutter the company and put an end to Sierra’s original adventures. What they intend to do with the Sierra catalog of IP remains to be discovered. logo_stop


Sources (Click to view; inert links are kept for historical purposes)

Softalk, “Tradetalk”, pg. 5, Sep 1980. “On-Line Systems has relocated from the hectic environs of the Los Angeles suburb of Simi to the more contemplative surroundings of Coarsegold, California, just outside of Yosemite Park.” Retrieved from the Internet Archive, Softalk collection, Oct 25 2015. 
Image of Roberta and Ken Williams together, as well as other information, from ROM, “Interview: Roberta Williams” by Peter Ellison, pgs. 8-9, Oct 1983. “…after that she [Roberta Williams] created the first computer adventure game with color, ‘The Wizard and the Princess’” ‘Time Zone’ has more than 1300 full-color computer-generated images compacted onto 12 disk sides.” “Q: …you came out with the massive program, ‘Time Zone’. What caused you to write such a huge game?   A: It was because in those days I played a lot of adventure games and I was always disappointed when they ended.” “Q: How long did it take you to complete ‘Time Zone’?  A: It took about six months.” Retrieved from the Internet Archive, ROM Magazine v1i8, Sep 27 2015. 
Image of Roberta Williams in 1984 from Electronic Fun With Computers and Games, “Gamemakers: Hi Res Sierra”, interview by Phil Wiswell, pgs. 30-33, Mar 1984. Retrieved from the Internet Archive, EFWCG collection, Sep 10, 2015.
Softalk, “Tradetalk”, pg. 50, Nov 1981. “The ad, in case you missed it in Time and Softalk, shows a hot tub with three taken women in it, discreetly submerged in water. The models and Roberta Williams (co-author of the Mystery Adventures and On-Line president Ken Williams’s wife). Susan Davis, On-Line bookkeeper, and Diane Siegal, production manager.” Retrieved from the Internet Archive, Softalk collection, Oct 28 2015.
Hackers – Heroes of the Computer Revolution, by Steven Levy –
Antic, “Roberta’s Bequest” by Tom Byron, pgs. 22 – 26, Mar 1990
Compute!, “Inside King’s Quest” by Donald B.Trivette, pgs. 136-139, Feb 1985
Roger Wilco’s Virtual Broomcloset –
Ahoy!, “Can the 64 Crack the Peanut?” by Steve Springer, pgs. 39-41, 90, Jan 1984
1981 image of Roberta and Ken Williams, as well as other information from Softalk, “Exec On-Line Systems” by Allan Tommervik, pgs. 4-6, Feb 1981. ” Roberta takes her foundation from literature. Mystery House was based on Agatha Christie’s Ten Little Indians (And Then There Were None) and the board game Clue; Wizard and the Princess was based on traditional fairy tales; and Mission: Asteroid was based on Lucifer’s Hamer by Larry Nevin and Jerry Pournelle.” Paddle Graphics and Tablet Graphics, On-line’s two graphic utilities, were devised for use in programming the mysteries in twenty-one hi-res colors.” “Both (Roberta and Ken Williams) desired a less urban environment in which to raise their two boys…” Retrieved from the Internet Archive, Softalk collection, Oct 26 2015.
New York magazine, “Star Tech: Safe at Home?” by Phoebe Hoban, pgs. 16-20, April 29 1985
The Human Element – Stage Select –
The Artful Gamer, Sierra’s “The ImagiNation Network Revived!” by Chris Lepine –”
Adventure Classic Gaming, Ken Williams Interview by Philip Jong, Mar. 28 2006 –
Compute!, “Readers Feedback: Fate of the PCjr” by the Editors of Compute!, pg.8, Aug1985

External Links (Click to view)

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