EAX          Accumulator for operands and results data
EBX          Pointer to data in the data memory segment
ECX          Counter for string and loop operations
EDX          I/O pointer
EDI           Data pointer for destination of string operations
ESI           Data pointer for source of string operations
ESP          Stack pointer
EBP          Stack data pointer

CS            Code segment
DS            Data segment
SS            Stack segment
ES            Extra segment pointer
FS            Extra segment pointer
GS            Extra segment pointer