In the Citadel you will get a quest from Dr Tidemann to visit Darwin Village to find a cure for cancer. Darwin Village is a higher level area with enemies that have a lot of HP and are significant in number. Fortunately they are slow are very easy to hit.
Once inside Darwin Village you will find an entrance to an underground complex.
Note: Having Rose in your party allows you instant access to the complex by simply "using" the console leading to the complex. Unfortunately if Rose IS in your party you cannot earn the achievement Sinister Legacy.
When you enter the second portion of the underground complex and progress through the area, you will reach a room that houses the cure you came for (In the section before the area that holds the air purifier, the room that houses the cure is behind a locked door to the West). In the same room is a computer on the desk. Using the Computer Science skill on the computer gives you the Wasteland 1 disk and unlocks the achievement.