Did you make any games like ZZT for the Apple II?

TS: Yeah. So I guess I was 11. The first serious game I wrote for the Apple II was -- the Apple II had this low resolution graphics mode, it was like 40 dots by 24 dots. But you had 16 colors to work with, which was just a huge number of colors.

So I made this game in the style of Atari's Adventure: you are a dot and you move the dot around the screen and you pick up different items and go between rooms, so I learned most of the basic programming techniques back then.

I started out writing one program for each room in the game world. So I'd write my own little input loop for each room, and then I realized, "Oh wow, there are subroutines, so I can call a subroutine to do an input." And that generalized everything.

Then I realized I could store the game board procedurally rather than writing a program to draw them and then reading the frame buffer to go from there. So I learned a huge amount of programming techniques that way. I was probably 12 or so, in probably 1982 or '83 when I wrote that.

Did you ever want to show those to the world? That would be pretty amazing. If you ever wanted to release those, I could help you copy the disks into disk images -- if you still have those disks.

TS: Sadly, I don't. It just didn't seem important. Yeah, that's the tragedy. I don't have the ZZT source code either. I wish I'd saved it all.

What happened to the source code? Did you lose it accidentally or...

TS: No, I just didn't pay attention to it. There were so many other things going on at the time. It was probably lost some time when we were working on five Epic projects -- you know, working with Cliff on Jazz Jackrabbit and James Schmalz on Solar Winds, and all these other games.

There were a few years at Epic where I'd gone from being a programmer, writing all of the games, to just managing projects -- I was basically a producer for about three years before I started working on Unreal as a programmer again. And that was crazy -- that was 16-18 hours a day straight for years.

The Origins of ZZT & Epic

Did your parents have any experience with starting businesses? Is that where you got the idea to start your own company?

TS: My older brother, Steve Sweeney, who's 15 years older than me, grew up in Maryland also, but then he moved out to the west coast and got involved in a bunch of start-ups in San Diego. When I was about eleven, I went out there several times to visit him. He was my role model for a few years there, because he was still pretty young and he was working for a bunch of cool companies.

I got to see the offices where he was working. He had all sorts of computers -- he was doing crazy things for minicomputers and mainframe communication at the time, and he'd be designing software and hardware drivers to run it. And he had a cool car and he had his own little house near the beach.

That was really cool, just to see that in the computer business, you didn't need to have an ordinary job at a company -- just go wear a suit every day. You could have fun between companies doing different projects. So that really was a big influence on me in deciding to start a company.

Take me through the process of when you started making ZZT.

TS: The funny secret behind ZZT is it started out while writing a text editor. I'd used Turbo Pascal and other languages on the PC, but I didn't like any of the editors that came with them, so I started writing my own.

I got bored with that at some point and decided to make the cursor into the smiley face character, and then make different characters you could type that would block the player or move around in different ways. See, you'd use this text editor to draw the game board and then move around it and play the game. That eventually evolved into the game and the editor ZZT.

It's funny, because ZZT is one of few things that started out as a tool before it was a game. And all the gameplay evolved from just thinking of random weird things to do with the characters. There were some other games along those lines like NetHack and Kroz.

I was going to ask you about Kroz. When I first saw ZZT, I thought it was a lot like Kingdom of Kroz from Apogee. Did that inspire you in any particular way?

TS: I'd been working on ZZT for several months -- I guess it was three or four months -- before I saw Kroz or NetHack or I realized anybody else had done anything like that. So I'd come up with a bunch of ideas on my own, and then I played all of those games and saw that there were a whole lot of other ideas to draw from.

For example, Kroz had these bombs where you have this little thing that looked like a bomb on the screen, and then you touch it, it starts a countdown, explodes, and clears out some blocks. So I borrowed a bunch of ideas from it at that point.

That's kind of a common pattern in everything I do. One minute I'm completely on my own and I think, "Wow, I'm a genius, I can't believe this idea nobody else had!" And then you look at the references on it, and it turns out that a hundred other people have done the same things in the 1980s. And then you look, and you get your additional ideas from those. Between invention and stealing, you come up with a really good combination of ideas.

When you were writing ZZT, where did you live? I read that you were going to school.

TS: I was in the University of Maryland at the time. Gosh, I guess I started in 1989 -- that was crazy. At that point, I was two years into college, going to school; I was doing mechanical engineering at University of Maryland. University of Maryland is a party school unless you're in engineering, so that was really tough, actually. I learned a lot of useful math that I wouldn't have learned on my own.

I basically studied and did school work all day, then programmed all night -- working on ZZT. On the weekends, I'd come home, and I had this little shareware business I was growing after I released the game.

I'd receive a bunch of orders through the mail (people would send their checks in), then I'd copy disks on the computer and send them out. At the same time, I was working on Jill of the Jungle, the next game.