X86-Secret : ES Zone
K5 Employee Use Only  (Week 48, Year 1996)   
AMD EMPLOYEE USE ONLY NOT FOR RESALE - AMD-K5 PR133

From 1995 to 1997, AMD Employees were able to buy cheap CPUs for their own uses. This sample was sold at Christmas '96 and comes from the Cafeteria at AMD HQ. It's a classic, production K5 PR133 but marked "Employee Use Only - Not for resale". AMD stamped some 486DX4 and K5 the same way.