The computer is located in the house through the portal in the flying castle. I can not for the life of me find the disk needed for it!! Where is the disk for the computer?
You have to make a Secret Potion by using the recipe found in the game's code:
1 Gold Bar
1 Iron Bar
1 Health Potion
After this, go to the Castle in the Sky and select "Give him a secret potion".
NOTE: The disc is a single-use item. After using it on the computer, it is removed from your inventory. If you want to use it again, you will need to make another secret potion and give it to the man in the Castle in the Sky.