| Name | 8 bit low | 8 bit high | 16 bit | 32 bit | 64 bit |
| Akkumulator | AL | AH | AX | EAX | RAX |
| Basis | BL | BH | BX | EBX | RBX |
| Count | CL | CH | CX | ECX | RCX |
| Daten | DL | DH | DX | EDX | RDX |
| Source Index | SI | ESI | RSI | ||
| Destination Index | DI | EDI | RDI | ||
| Base Pointer | BP | EBP | RBP | ||
| Stack Pointer | SP | ESP | RSP | ||
| 8 | R8B | R8W | R8D | R8 | |
| 9 | R9B | R9W | R9D | R9 | |
| 10 | R10B | R10W | R10D | R10 | |
| 11 | R11B | R11W | R11D | R11 | |
| 12 | R12B | R12W | R12D | R12 | |
| 13 | R13B | R13W | R13D | R13 | |
| 14 | R14B | R14W | R14D | R14 | |
| 15 | R15B | R15W | R15D | R15 | |
| Instruction Pointer | IP | EIP | RIP | ||
| Flags | FLAGS | EFLAGS | |||
| Code Segment | CS | ||||
| Stack Segement | SS | ||||
| Daten Segment | DS | ||||
| Extra Segement | ES | ||||
| Extra Segement | FS | ||||
| Extra Segement | FS | ||||
