Long ago, in the heroic days of the Sierra Adventure Games, in the middle 80 yearsthe game was just released: Space Quest II. Thousands of players then rushed to get it (on diskettes) to go on new crazy space adventures. Nothing unusual so far.
Except… in reality these Space Quest II (SQ2 for short) floppies hide a an incredible secret that no one has discovered until today ! Indeed, on most of the game’s floppies (versions 2.0D and 2.0F), the Sierra developers accidentally left almost 70% original source code of their AGI game launcher (Adventure Games Interpreter)!
Because yes, on these floppy disks that ran on every personal computer on the planet, there was not only the game, but most source code that is normally kept secret which has powered all their games since the first King’s Quest!
But how could something like this happen?
Well, quite simply because of a small handling error when preparing the master diskettes for duplicating. At the time, the floppy disk manufacturing process involved copying entire sectors of the main disk, including free space. Except, unfortunately, the master disks used for SQ2 previously contained AGI source code. The files were deleted, but the data was still present in the unused sectors. And with the duplication, presto, the source code ended up without Sierra’s knowledge on the floppy disks of tens of thousands of players!
A simple DIR command on the floppy directories revealed nothing abnormal. The main game files, such as PICDIR, LOGDIR, VIEWDIR, SNDDIR, VOL.0 and VOL.1they were indeed dated March 1988. However, the free space on diskette 1 of version 2.0D contained fragments of source code from the deleted files, but not completely deleted and discovered simply with the help of a hex editor.
Picking at the recesses of floppy disks, Lance Ewing was able to find it 93 source files scattered in forgotten regions! Most of these files are written in C language, there are few batch scripts left for assembler and DOS. A real Ali Baba’s cave for lovers of retro code.
The crazy thing about this is that some of these C files even contained comments and modification history ultra detailed! Therefore, we can see the names of developers, dates, descriptions of each change… etc. It is a real archaeological treasure to understand how these pioneers of adventure games worked at the time.
This is how we learn that the AGI code was mostly developed by him Jeff Stephenson and Chris Eden between 1985 and 1987, with the last changes in early 88. We see their tireless work on constantly improving the code, optimizing, fixing bugs, adding new features. The crazy job that paved the way for all Sierra adventures: King’s Quest, Larry, Space Quest, Police Quest…all those legends of the genre have passed through this brilliantly oiled software machinery!
Just imagine if this AGI source code really ended up in the wrong hands at the time, like an unscrupulous competitor… They could have discreetly recovered it and used it in their own games, stealing all the details of Sierra’s revolutionary idea shame (well, a little bit). Fortunately this little security incident remained without consequences. A miracle when you think about it!
Lance had the good idea to share all his discoveries AND GitHub repository dedicated So a word of advice to old school code lovers, it’s a gold mine to explore! In addition, he developed his own modern AGI interpreter based on this original source code, to run all these classics directly in the browser. The man appointed AGILEa project as crazy as it is admirable for you to test with real games here.
And if you also have old floppy disks lying around, it might be worth looking at them in the hexa editor, because you never know, they might have been erased incorrectly before going to the master and you might discover some funny things there.