'Welcome to the dungeon' was the message that flashed up on computer screens in 1986.
This was thought to be the first virus for personal computers and became known as 'Brain'.
'Brain' spread around the world and became infamous when it was featured in newspapers and magazines.
Amjad Farooq Alvi tells Gill Kearsley how he and his brother, Basit, came to develop this accidental virus from their shop in Lahore, Pakistan.
(Photo: The 'Brain' computer virus. Credit: Amjad and Basit Alvi)
