Marc Blank | Code Like It's 198x

In 1977 Marc Blank was a medical student. He was also one of four people at MIT writing Zork, a game played by typing English sentences at a mainframe. He qualified as a doctor in 1979 and, as COMPUTE!’s Gazette put it four years later, “decided not to pursue that profession, opting for what he considered a more creative field”. That field was Infocom, which he helped found. Blank and Joel Berez designed the virtual machine that let Infocom’s games run on almost any home computer. He co-wrote the Zork trilogy and Enchanter, and he wrote Deadline, the murder mystery whose box of clues began Infocom’s habit of packing real objects with its games.

Fast facts

Born: 1954.
Education: MIT in the mid-1970s; medical school at Albert Einstein in New York, graduating in 1979.
Infocom: one of its ten founders in June 1979; vice-president by 1983, and vice-president for product development by 1984.
Games: Zork I (1980), Zork II (1981), Zork III (1982) and Enchanter (1983), all with Dave Lebling; Deadline (1982), Border Zone (1987) and Journey (1989) on his own.
Technology: the Z-machine, with Joel Berez, 1979.
After Infocom: Blank, Berlyn and Co., later Eidetic, with Michael Berlyn, from late 1993; Syphon Filter (1999).
Honours: the Academy of Interactive Arts & Sciences’ Pioneer Award, with Dave Lebling, in 2013.

Zork at MIT

Blank first played Adventure on a PDP-10 mainframe some time in 1977, he told the German magazine PC Player in 1999. He belonged to the Dynamic Modelling Group at MIT’s Laboratory for Computer Science, though he was training to be a doctor rather than studying computing. The game made them ambitious. “Colossal Caves was the only adventure around,” he said in 1984. “So after we played it and liked it a lot, we asked, ‘Why don’t we do something like it?’”

The authors were Tim Anderson, Bruce Daniels, Lebling and Blank. They wrote it in MDL, a LISP-like language developed at MIT, and the first version was playable in June 1977. “The old Zork was very small, with just a two-word parser,” Blank recalled. “We realized that was really very limiting, so we expanded the parser and invented new problems. Eventually Zork, between 1977 and 1979, got really, really large. It was just a hodgepodge of different sorts of things; whenever anyone had a good idea for a problem, we’d add it.” That mainframe game later became, he said, almost all of Zork I, half of Zork II and a tenth of Zork III.

Infocom and the Z-machine

Infocom was founded on 22 June 1979 by ten members of the laboratory. Blank was one of them, and he graduated from medical school the same year. The company’s first problem was how to fit a mainframe game of about a megabyte onto home computers with 32K of memory. Retro Gamer’s history of Infocom says that Berez and Blank had each, independently, worked out the first part of the answer.

Blank and S. W. Galley described it in Creative Computing in July 1980. Infocom wrote its games in ZIL, a cut-down MDL, and compiled them for “a ‘virtual machine,’ specifically designed to execute Zork programs; the virtual ‘Z-machine’ has a machine language called ‘Z-code’”. Each real computer needed only a small interpreter, which loaded the game from disk in 256-byte pages as they were needed. The instruction set was designed for adventure games, and that made the code small. Zork’s parser, they wrote, filled “10K 36-bit words” on the PDP-10, while the Z-code parser, “which is actually better functionally, occupies only 3K 8-bit bytes”. Text was packed at “about five and a half bits per visible character”. Lebling’s example in BYTE that December was moving an object from one room to another, which “takes just 3 bytes of storage”. Porting a game meant writing one interpreter, and by the end of 1980 there were interpreters for the Apple II, the TRS-80, the PDP-10 and the PDP-11.

Berez and Blank became Infocom’s first full-time employees. The mainframe game was split up, and Zork I appeared in 1980, Zork II in 1981 and Zork III in 1982, credited to Blank and Lebling. “When we put the games on micros, especially Zork II and III, we tried to give them a plot, which the original didn’t have at all,” Blank said.

Deadline

Deadline (1982) was Blank’s own game, and Retro Gamer puts it down to his love of detective novels. The wealthy Mr Robner has been found dead in a locked room, officially by his own hand, and the player is the police inspector with twelve hours to prove it was murder. The household carries on around the investigation. SoftSide’s reviewer in 1982 could talk to “Mrs. Robner, the bereaved widow, as she eats breakfast”, and warned that a hurried player might find clues “before Mrs. Rourke innocently takes them away”. There was not room in the game for all the evidence, so Blank asked Infocom’s advertising agency to make it as real objects. The case folder in the box held the coroner’s report, interview transcripts, a photograph of the body and “Exhibit A — a packet of pills found near the body”. These extras became an Infocom trademark, later known as feelies.

Blank described working the other way round from Zork: “There’s a plot, and then we say, ‘Well, what are the problems going to be?’ In Deadline, for instance, we said, ‘Okay, the story is this, and this guy’s dead, and these people are going to do this and that. Now, what’s the game, what are the pieces of evidence and what can you do?’” His colleague Michael Berlyn said Deadline had changed what detective games were like, “with characters that move around independently, whose lives you can affect, with time flowing through the story and with things happening whether you’re there or not”. By 1984 Blank could report that “Zork and Deadline sell well. They’re often the first games like this people play.”

Infocom’s vice-president

At 28, Blank told COMPUTE!’s Gazette in October 1983 that Infocom’s “adventures are more like books than games”, and that “an adventure game is only as good as its parser”. By June 1984, when Family Computing interviewed him with Berlyn, he was vice-president for product development, Zork I had sold more than 250,000 copies, and he and Lebling had just released Enchanter, the first of a new trilogy in which the player is a magician. He wanted the machine to disappear: “The idea is to make the computer invisible. You don’t want to know you’re dealing with a computer. You want to be interacting with the story, and anything that gets in the way, having to swap disks or communicate in two words, detracts from the experience.” Time magazine had just called Infocom’s stories “crude” by literary standards. “We’re going to put stickers on our packages that say ‘Crude! Clumsy!’—Time magazine,” Blank joked.

He and Berlyn also started Fooblitzky, a computer board game for two to four players, which Infocom was test-marketing by mail order when Computer Gaming World reported it in January 1986.

Border Zone and Journey

By the end of 1987 Blank was, in COMPUTE!’s words, “lately a free-lance developer and consultant”. Infocom, by then owned by Activision, published his Border Zone late that year: three linked spy scenarios around the border of the imaginary Eastern Bloc country of Frobnia, each played as a different character, with a clock that ran in real time. “My goal in writing it was to make it a storytelling experience,” he said. “There are puzzles, of course, but the puzzles are so embedded in what’s happening in the story itself that you almost forget that they’re puzzles.” Computer Gaming World’s adventure columnist, Scorpia, was disappointed. She found most puzzles “trivial” and called it “one of Infocom’s weakest games to date”, adding that had she “not seen his name on the box”, she would not have believed it was his.

Journey (1989) dropped typing altogether. Infocom advertised it as one of its new “role-play chronicles”: it “requires no typing and can be played entirely with a keyboard, a joystick, or a mouse”, and had “over one hundred” pictures.

After Infocom

After Journey, Blank stepped away from adventure games. When COMPUTE! spotted him at a reunion of former Infocom staff in 1993, it described him as the “ZorkMaster” who had “vanished from the adventure game scene after Activision bought Infocom”. Late that year he and Berlyn started their own development company. Its first products were for Apple’s Newton handheld, Columbo’s Mystery Caper and Dell Crossword Puzzles. The company became Eidetic, based in Bend, Oregon, and went on to PlayStation games: Bubsy 3D in 1996 and Syphon Filter in 1999. Syphon Filter, Blank told PC Player, was about as far from a text adventure as anyone could imagine. He was no longer much involved in the genre, he said, though the small text adventure inside Zork: Nemesis was his work, and with Berlyn he wrote Zork: The Undiscovered Underground, a free text adventure that Activision released in 1997. Sony bought Eidetic in 2000.

Blank later moved into software outside games. In 2004 he was writing ChatterEmail, an email program for the Palm Treo smartphone; Palm later bought the program and hired its developer. In February 2013 he and Lebling received the Academy of Interactive Arts & Sciences’ Pioneer Award, the first pair to receive it together, for games such as Zork and Enchanter. The greatest reward, he had said in 1999, was being told by people in the industry that his games had inspired them as teenagers to become designers, programmers or producers. That had happened, he said, more than a dozen times.

Released source code

The source code of the Zork trilogy was released under the MIT licence by Microsoft in November 2025 (see Zork). In April 2019 the archivist Jason Scott put the ZIL source of Infocom’s other games on GitHub, including Blank’s Deadline, Enchanter, Border Zone and Journey; those repositories state no licence.

Sources

Kathy Yakal, “Marc Blank: The Programmer Behind Zork”, COMPUTE!’s Gazette issue 4, October 1983, pp. 64–66: his age and post; MIT and Adventure; MDL, the PDP-10 and the first version in June 1977; medical school at Albert Einstein and graduation in 1979; “more like books than games”; the parser.
Eric Grevstad, interview with Marc Blank and Michael Berlyn, Family Computing, June 1984, pp. 38–41: vice-president for product development; Adventure and the growth of Zork; plots for Zork II and III; designing Deadline; sales; Enchanter; “make the computer invisible”; Time and the stickers; Berlyn on Deadline.
“From Zork to Zero: The Infocom Story”, Retro Gamer issue 10, 2004, pp. 30–37: the Dynamic Modelling Group and Blank’s medical training; the founding on 22 June 1979 and the ten founders; Berez, Blank and the Z-machine; the first full-time employees; Deadline, detective novels and the extras in the box; the release timeline.
Marc S. Blank and S. W. Galley, “How to Fit a Large Program Into a Small Machine”, Creative Computing, July 1980, pp. 80–87 (text online): ZIL, the Z-machine and Z-code, the parser sizes, five and a half bits per character, 256-byte pages. https://mirrors.talideon.com/articles/zmachine.html
P. David Lebling, “Zork and the Future of Computerized Fantasy Simulations”, BYTE vol. 5 no. 12, December 1980, p. 172: the four authors; the “Zork-language virtual machine”; the three-byte instruction; interpreters for the Apple II, PDP-11, PDP-10 and TRS-80; Blank and Galley’s article.
Retro Gamer issue 12, 2005, p. 34: Enchanter “by Marc Blank and Dave Lebling”.
Computer Gaming World issue 25, January 1986, p. 40: Fooblitzky, started by Berlyn and Blank, test-marketed by Infocom.
Keith Ferrell, “Infocom Faces The Challenge: A Conversation With Joel Berez And Marc Blank”, COMPUTE! issue 92, January 1988, pp. 17–19: Blank as a freelance developer; Border Zone, its scenarios and real time.
Scorpia, review of Border Zone, Computer Gaming World issue 43, January 1988, pp. 20–23: Frobnia, the scenarios and the verdict.
Review of Deadline, SoftSide vol. 5 no. 11, August 1982, p. 82: the case, the household and the contents of the case folder.
Amiga Power issue 6, October 1991, p. 89: Deadline’s twelve hours, “written in 1982 by” Marc Blank.
Infocom advertisement for Journey, COMPUTE! issue 105, February 1989; Computer and Video Games issue 93, July 1989, adventure column: Journey as a “role playing chronicle” by Blank.
COMPUTE! issue 156, September 1993: the reunion of Infocom staff and Blank’s absence since the Activision takeover.
COMPUTE! issue 161, February 1994, p. 92: Blank and Berlyn’s company, formed late in 1993, and its Newton games.
Official US PlayStation Magazine vol. 2 no. 6, March 1999: Syphon Filter by Eidetic, whose previous game was Bubsy 3D.
Interviews with game designers, PC Player (Germany), April 1999, p. 148: Blank on Adventure in 1977, the share of the mainframe Zork in each part of the trilogy, Zork: Nemesis, Syphon Filter, and being told his games had inspired others.
Wikipedia, “Marc Blank” (accessed October 2026) (web, secondary): his year of birth; the company’s name, Blank, Berlyn and Co., and its renaming as Eidetic, in Bend, Oregon; Zork: The Undiscovered Underground; Sony’s purchase of Eidetic in 2000; ChatterEmail and Palm. https://en.wikipedia.org/wiki/Marc_Blank
IFWiki, “Marc Blank” (web, secondary): Zork: The Undiscovered Underground (1997), with Michael Berlyn. https://ifwiki.org/Marc_Blank
Michael Ducker, “Chatter Update”, TreoCentral, 30 August 2004, and “Palm Discontinues ChatterMail App”, TreoCentral, 12 March 2009 (web, secondary): ChatterEmail, and Palm’s purchase of it. https://treocentral.com/content/Stories/444-1.htm
“Infocom founders to be honored at D.I.C.E. Awards”, Game Developer, 19 December 2012 (web, secondary): the Pioneer Award. https://www.gamedeveloper.com/business/infocom-founders-to-be-honored-at-d-i-c-e-awards
historicalsource on GitHub, repositories deadline, enchanter, borderzone and journey, created April 2019 (web). https://github.com/historicalsource