INTEL CONFIDENTIAL - DC1EC501A400 KATMAI - O82528SUA0-0028 A4

This CPU labeled with the "KATMAI" codename, is an early engineering sample clocked at 400 MHz. It was produced in June 1998. The first Pentium III, clocked at 450 MHz, were launched in 23th February 1999, 10 months later. The sample comes with 512 KB of L2 on a Pentium II cartridge. It needs a special motherboad to activate the cache properly, trying on a standard one results in a disabled L2. The CPUID of this CPU is 0x670 (A0 stepping) where the first commercial samples uses 0x672.