Intel 8086 Family Architecture
General Purpose Registers Segment Registers AH/AL AX (EAX) Accumulator CS Code Segment BH/BL BX (EBX) Base DS Data Segment CH/CL CX (ECX) Counter SS Stack Segment DH/DL DX (EDX) Data ES Extra Segment (FS) 386 and newer (Exx) indicates 386+ 32 bit register (GS) 386 and newer Pointer Registers Stack Registers SI (ESI) Source Index SP (ESP) Stack Pointer DI (EDI) Destination Index BP (EBP) Base Pointer IP (EIP) Instruction Pointer Status Registers FLAGS (EFLAGS) Status Flags (see Flags Register) Special Registers (386+ only) CR0 Control Register 0 DR0 Debug Register 0 CR2 Control Register 2 DR1 Debug Register 1 CR3 Control Register 3 DR2 Debug Register 2 DR3 Debug Register 3 TR4 Test Register 4 DR6 Debug Register 6 TR5 Test Register 5 DR7 Debug Register 7 TR6 Test Register 6 TR7 Test Register 7 Register Default Segment Valid Overrides BP SS DS, ES, CS SI or DI DS ES, SS, CS DI strings ES None SI strings DS ES, SS, CS - see CPU DETECTING Instruction Timing