The Reconstruction of ZZT

For those who are unaware, ZZT was a text-mode DOS adventure game written in 1991 by the founder of Epic Games, Tim Sweeney.

It included a level editor and scripting language, which allowed anyone to unleash their creativity and design their own text-mode games using the ZZT engine.

This was absolutely unique at the time.

As a company, Epic is still hugely successful. Most gamers in 2020 have probably heard of Fortnite and Unreal Engine. According to Wikipedia, Tim Sweeney still owns over 50% of the company.

ZZT explored a lot of ideas about how to build a game creation system, which influenced Unreal Engine, which itself was hugely influential throughout the game industry.

The standard paradigms for today's game engines and editors was clearly influenced by ZZT.

This is fantastic. Tangentially, I did not know the source code was lost:

"Please don't ask for the source; if I had it, I'd release it, but I lost it in a crash a long time ago." -Tim Sweeney

https://web.archive.org/web/19991010013339/http://www.epicga...

I find the whole thing interesting, because I remember the shareware versions that I downloaded from my friendly neighborhood BBS offered the source code for a fee; a large fee, if memory serves. I wonder if any of the purchasers of said source code might still have it sitting around on their floppies somewhere.

"The output executable is byte-for-byte identical with said release, which means that the source code accurately represents the original engine's behavior."

That seems crazy that someone could reverse engineer compiled code back into the higher level language it came from, and then have that code compile into the exact same executable. Obviously, you can keep modifying the code until it matches, but it's still impressive for anything other than a small program.

This is awesome. ZZT was huge for me when I was young. I had already been toying with making games and desktop programs in VisualBasic by the time I found ZZT, but the ability to just throw together little worlds and play with the basic primitives the game gave us, share them with friends, was such an experience for the time.

I wonder how kids today would see ZZT. I think they'd have a lot of fun with it once they got into it, but being an older DOS-based game, ASCII art and all, might be particularly strange to some. A lot of modern games, Minecraft being one that immediately comes to mind, invoke the creativity and that ZZT did in my generation. Still, I'd love to see what people would make in ZZT today.

Tangent: I can't believe it was this long ago now, but about 10 years ago I started working on reverse-engineering ZZT with the goal of putting together a web-based implementation that was compatible. That spiraled out of control into a brand new project I called MWorlds (https://mworlds.wordpress.com/).

Haven't toyed with this in ages, but the idea morphed into an open platform for making web-based games, including all assets (sprites, music, script packs, monsters, weapons, etc.), that any kid or adult could build and share and use in their own games. I really should just open source this someday. Or start hacking on it again.

ZZT was amazing, probably one of the earlier games that had - and still has - a massive modding community. I remember the one day we got a CD with a load of demos, games, etc in a magazine, which in addition to a Shockwave menu also just had the file structure; in there, we found a folder full of ZZT games.

A really memorable one was Code Red (https://museumofzzt.com/file/c/codered.zip), which just had so many little interactive things in at least the first area; a television set with multiple programs, a vacuum that would follow you around and explode if you vacuumed the wrong thing, it just kept giving. I don't actually remember getting very far in it though.

Anyway, more recently I got a similar "feel" that I got from ZZT back in PICO-8, a virtual console with a very accessible yet simple and intentionally limited editor; like ZZT, it gives you all the bells and whistles to create a game, but it's simple enough to avoid you reaching beyond the point where you can finish it. It having a built in game explorer (with online connectivity) means you've got thousands of indie games to explore. It's more versatile than ZZT, but still keeps you sane.

This is awesome.

Who would have guessed of all the games I was playing in 1993 that ZZT would be the one where the creator went on to become a billionaire...

This is so lovely to see! ZZT got me into programming in a very holistic, human, way. I'm happy that it's being explored.

There's a link in there to the Museum of ZZT: https://museumofzzt.com/about-zzt.

Looking through the screencaps brings back a flood of memories. I remember playing a lot of DOS games where you had colored ASCII art and that was it. You really had to use your imagination to immerse yourself in the game and the default levels did a good job of conveying that.

Today's games look amazing. It's crazy to think that these text games could make you feel like you were in the game.

ZZT is great. Without it, we wouldn't have gotten MegaZeux. Both had really fun communities

This is amazing, and I am incredibly glad someone has put in the legwork to see this to fruition. I spent hours with it as a kid, both with it and its unofficial successor Megazeux.

ZZT was a fun game creation system out of the box, but what always impressed me was some of the stuff that the community managed to come up with - mostly documented in the ZZT encyclopedia series as well as the Super Toolkit. It pushed the engine far beyond the limits of what it was intended for, and some the projects done with it absolutely blew my mind.

It was unfortunate that the source was lost, and for a long time the best you could do, aside from DOSbox, were projects like DreamZZT which, while admirable, didn't accurately emulate all of the peculiarities that many games relied on. But now this exists. Thank you.

This is something I have seen. I have used ZZT, and it is still used even now. One of my ZZT games includes a note that although the world itself is Free software, it is "trapped" because ZZT isn't. That was written before ZZT source code has been reconstructed in this way, and now ZZT is Free software, although it is itself "trapped" because the compiler isn't. There are many tricks and stuff involved in ZZT and I have figured out some things just by trying and then make the hypothesis how they worked, and now I can check the source code to see if it matches what I expected, too. But I can see in there also many things I did not know ZZT does, so this is helpful. Other people have also independently figured out many kind of tricks with ZZT (see [0] and [1] for some details). I also wrote my own external editor for ZZT (although unfortunately it is slow, and confusing, but I like it, and prefer that kind of user interface, which is why I wrote it, of course).

There are now other ZZT-likes, the most popular of which is probably MegaZeux (which is now Free software, and continues to be maintained), although there is also ZIG, and a few others, including my own ZZ Zero. Each of them has different set of features. Although, most of them aren't used much other than ZZT and MegaZeux, I think.

The GitHub mentions to fix 5 annoying bugs in ZZT. I thought of fixing some bugs in ZZT (although not those that affect the behaviour of the game), and removing the editor (you can use an external editor instead, such as KevEdit or ZZTQED) and any stuff that is in there because it is only used by the editor, and probably also removing mouse and joystick mode and monochrome mode and VideoWriteTextCO40 (I don't know why that is in there, since ZZT doesn't use the forty column mode), and removing the initial prompt (to make it faster to load and further reduce the file size), and possibly adding an additional optional header in the world file which controls some new features and bug fixes, and allows customizing the contents of the ElementDefs array (the first number in the file would be different, so you can tell apart from standard ZZT worlds). I don't know when or if I might try to do this, though; I will of course need to install Turbo Pascal first, and read its documentation, before I could do such a thing.

[0] https://rabbitboots.com/kfx/index.php/ZZT_Notes

[1] https://rabbitboots.com/kfx/index.php/ZZT_On_ZZT

asiekierka, I'm very impressed. How did you go about building this? Did you start with the assembly and work backwards to Pascal? Did you use a Pascal decompiler? Even then I can't imagine how you managed to get the output byte-for-byte equivalent...

Anyway, as someone who downloaded ZZT from BBSes and wrote ZZT-OOP back in the day, I love this. I recently started writing a version of ZZT in Go, but haven't progressed since being able to load and display worlds. :-|