Mobile Module Connector 1 (MMC-1), is a 280-pin microprocessor cartridge developed by Intel for used by their mobile Pentium, Pentium MMX, Pentium II and Celeron processors. It contains the microprocessor and its associated L2 cache, a 430TX for the Pentium or a 443BX for the Pentium II northbridge, and a voltage regulator.
MMC-1 was more of a mechanical standard than an electrical one, since the southbridge of the 430TX chipset would not work correctly with the northbridge of the 443BX and vice versa. This was irrelevant for MMC-2 since the northbridge was always the 443BX.