The Free On-line Dictionary of Computing (30 December 2018):

Socket 370
PGA370

    (PGA370) A physical and
   electrical specification for a motherboard processor
   socket.  Socket 370 uses a square SPGA ZIF socket with 370
   pins, arranged 37x37 (sometimes described as 19x19).

   Intel originally designed Socket 370 for PPGA Celeron
   processors.  Newer Socket 370 motherboards additionally
   support FC-PGA Celeron and Pentium III processors.

   The difference between the two versions is electrical;
   some pins are used differently and voltage requirements have
   been changed from Intel's VRM 8.2 to VRM 8.4.  In
   addition, Celeron processors require a 66 MHz front side bus
   (FSB), and Pentium III processors require a 100/133 MHz FSB.

   Some older Socket 370 motherboards support VRM 8.4 and
   variable bus speeds, so adapters are available that convert
   the socket pinout to allow FC-PGA processors to work.

   VIA's Cyrix III processor was designed to work with
   Socket 370 motherboards.

   Intel Celeron Processor in PPGA form factor - Integration
   (http://pentium.com/design/quality/celeron/ppga/integration.htm).

   Pentium III Processors - Design Guidelines
   (http://intel.com/design/PentiumIII/designgd/).

   (2000-08-26)