Index - D
| dataBus | Nes.Bus.State |
| dcp | Nes.CPU.Instructions.Unofficial |
| dec | Nes.CPU.Instructions.Arith |
| decayLevel | Nes.APU.State.Envelope |
| DecimalMode | Nes.CPU.State |
| defaultOutputRate | Nes.APU.State.Filter.Constants |
| delayedWriteSideEffectCycle | Nes.APU.State.FrameCounter |
| delta | Nes.APU.State.Filter.Iir |
| dex | Nes.CPU.Instructions.Arith |
| dey | Nes.CPU.Instructions.Arith |
| DirtyFrame | Nes.Render.Monad |
| disableLengthCounter | Nes.APU.State.LengthCounter |
| divider | Nes.APU.State.Envelope |
| dividerCounter | Nes.APU.State.Pulse |
| dividerPeriod | Nes.APU.State.Pulse |
| DMC | |
| 1 (Data Constructor) | Nes.Interrupt |
| 2 (Type/Class) | Nes.APU.State.DMC |
| dmc | Nes.APU.State |
| Down | Nes.Controller |
| dt | Nes.APU.State.Filter.Chain |
| dutyIndex | Nes.APU.State.Pulse |
| dutyStep | Nes.APU.State.Pulse |