Enter the maze

The Pentium Chip Error, 1994

Not enough numbers in the table.

The Pentium Chip used a look-up table to do division; basically it uses a pre-calculated set of numbers to speed things up. The look-up table should have contained 1066 elements, but when the numbers were downloaded a bug in the software only put in 1061 of them. No one checked, and the chip went to manufacture with those numbers missing. When the mistake was found the chips had to all be replaced. The cost was more than $4 billion.

The moral: keep testing all the way.