Drop a .nes ROM file here or use File > Open ROM...
No ROM loaded
NTSC
Audio: On
State: empty
ROM Information
X
Filename:
-
Format:
-
Mapper:
-
PRG ROM:
-
CHR ROM:
-
Mirroring:
-
Battery:
-
Trainer:
-
TurtleNES
X
!
CPU Debugger
X
Disassembly
Registers
A
00
X
00
Y
00
SP
00
PC
0000
P
00
Flags
PPU
Scanline
0
Dot
0
Frame
0
CPU Cycles: 0
Memory Viewer
X
Page:
Pattern Tables
X
Table $0000
Table $1000
Palette
Nametable Viewer
X
About TurtleNES
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TurtleNES v1.1
A Nintendo Entertainment System emulator, written from scratch in JavaScript.
No external emulator cores were used. The 6502 CPU, PPU, APU, and mappers are all implemented directly in this project.
This program does not include or distribute any commercial ROM files. Please use your own legally obtained ROM dumps.
TurtleNES
X
i
Configure Controller 1
X
Click a button name, then press the key to bind. Esc cancels.
Input Display
X
CPU Compatibility
X
Undocumented opcodes are side effects of the 6502 design that the manufacturer never documented (LAX, SAX, DCP, ISC, SLO, RLA, SRE, RRA and others). A few games and test programs use them. Leave this on "Official opcodes only" unless a game needs the extras. With official-only mode, running an undocumented opcode halts the CPU.
Custom Speed
X
Emulation speed (0.1 to 10):
x
Audio is muted while the speed is not 1x.
Rewind
X
History length:
Timeline
No history yet.
Hold Backspace (or the Rewind toolbar button) to rewind. Drag the timeline to jump to a point, then press Run to continue from there.
Cheats
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Code: Name:
Format: AAAA:VV writes hex value VV to address AAAA every frame. AAAA:VV?CC only writes while the byte currently equals CC. Addresses must be in work RAM ($0000-$1FFF) or cartridge RAM ($6000-$7FFF). Cheats never change the ROM and are not part of save states.