There are several variants of the 6502 CPU. The following abbreviations are used to specify compatibility:
| Variant | Available on |
|---|---|
| 6502 | 6502 |
| 60C02 | 6502, 60C02 |
| R | Rockwell 60C02 and newer Western Design Center 60C02 |
| WDC | only Western Design Center 60C02 and 65816 |
| 65816 | 6502, 60C02, 65816 |