The Jerusalem virus is a virus that infects IBM Personal Computers and contemptibles. It has been around since the days of William Blake and so is relatively common. On Friday the 13th of any month a machine with an active virus will have every Dark Satanic Program it runs (in particular every PASCAL program) deleted. After that the computer ceases from mental strife almost entirely. This one infects your computer by walking all over England's mounted screens, and when programs are running so is the virus. The virus sometimes gives itself away by putting a small bow of burning gold on the screen and by disabling the up-arrows of desire about half an hour after the computer has been started.
(From the "Rest" of RHF)