1	ISA (Industry Standard Architecture) bus slots for plugging in older 8 and 16-bit adapter cards.
2	PCI (Peripheral Component Interconnect) bus slots for plugging in newer 32-bit adapter cards.
3	Hard drive controller connectors.
4	Power connector.
5	Parallel port connector.
6	Floppy disk controller connector.
7	SIMM (Single In-line Memory Module) sockets for adding memory.
8	Lithium backup battery for the CMOS.
9	Configuration jumper block for changing the ISA bus clock, clearing a CMOS password, resetting the CMOS to the default settings, etc.
10	Front panel connectors for the internal speaker, keyboard and hard drive lights, +12v fan, etc.
11	Pentium processor in a Socket 5 connector.
12	256K cache (those systems with an external cache only).