NESpot

NESpot is a platform-independent NES emulator. It's written in Kotlin, so compiles to either a standalone JVM app or JavaScript that runs in a browser.

Whilst game coverage is increasingly reasonable, the lack of full cycle accuracy means that various games don't work properly (or at all).

Running as an app

./gradlew run --args "[<options>] <rom>"

NESpot is developed and tested against JDK 11. It may work with older Java versions, but this has not been tested.

Options

Option	Description
-f / --fullscreen	Full-screen mode
-i / --info	Print ROM info

Running in a browser

Put your ROMs in the roms/ directory. Then:

./gradlew jsBrowserProductionRun --continuous

Then visit http://localhost:8080/<rom> (without a .nes suffix).

Key bindings

Key	Effect
Up/Down/Left/Right	Controller D-pad
Z	Controller A
X	Controller B
[	Controller Select
]	Controller Start
F	Toggle full-screen mode
R	Reset
Cmd+Q	Quit

Known game coverage

Game	SHA-1 (PRG+CHR)	Mapper	Status
Arkanoid	230FC31D2C2EB20E78711C82574F29F28117EBA3	3	✅ No known issues.
Bart Simpson vs. the Space Mutants	84675A1966384AFDB0715672207ECE3997B92033	1	✅ No known issues.
Battletoads	D85C9FF489672534FBF61A15F8FA56FFF489A34B	7	✅ No known issues.
Bomberman II	2E401097B7B6F5DE5B0F88E6A97C5675BD916801	1	✅ No known issues.
Bubble Bobble	C1A8F6A9316080487CFEACA62F3D573CD9D484E9	1	✅ No known issues.
Bubble Bobble 2	19783C0724A495316FFA54F5D85A5729D6FE637E	4	✅ No known issues.
Castelian	847D56E43754E402666A91188520737094E9ECFA	2	✅ No known issues.
Color a Dinosaur	B84C5A8EA62EF3F1EEF920968284DC6CD4D6055D	2	✅ No known issues.
Dizzy the Adventurer	5A4EF3B2F5880D3B4609AE4F3381D688B3A02CAC	71	✅ No known issues.
Donkey Kong	D222DBBA5BD3716BBF62CA91167C6A9D15C60065	0	✅ No known issues.
Fire Hawk	334781C830F135CF30A33E392D8AAA4AFDC223F9	71	❌ Unplayable. Graphical glitches + hangs.
Hook	EAE5205928D3FA2AFEA0374B457D2BB91E414D99	1	✅ No known issues.
Indiana Jones and The Last Crusade	36EC0A750888DB2BAAA21651528807D70CA97C6B	1	✅ Very playable. Graphical glitches on splash screen.
Jurassic Park	57F755C6A10C6681761070B0350DA72432A534E9	4	✅ No known issues.
Kirby's Adventure	118307DA6C77A592F0884BAAD14120301D8D3A1B	4	✅ No known issues.
Legend of Zelda	A12D74C73A0481599A5D832361D168F4737BBCF6	1	✅ Very playable. One known minor bug.
Micro Machines	C7FD43041FC139DC8440C95C28A0115DC79E2691	71	✅ Very playable. A few graphical glitches.
MIG-29 Soviet Fighter	B74802F946D99A83E8E223B6F987E6482A8EC41D	71	✅ No known issues.
New Zealand Story	EA388B7B826E14CB907FBEDC1651EE831FB22D41	4	✅ No known issues.
Pacman	92C3361B9E3B28A51FD30E7845C988A6D576EE65	0	✅ No known issues.
Prince of Persia	9BC0211CF659608E375AA2D29CEC1ECDE463CF29	2	✅ No known issues.
Solomon's Key	222E19511D64872E0B47A47D77ECC9BB3EBC52DC	3	✅ No known issues.
Space Harrier	AEE6BB2338E71CC9390FBB845225C19E194CDD21	1	✅ No known issues.
Super Mario Bros	FACEE9C577A5262DBE33AC4930BB0B58C8C037F7	0	✅ No known issues.
Super Mario Bros 2	C10575DBB211A5AB5321573D884041FE35BD15E3	0	✅ No known issues.
Super Mario Bros 3	A611B90B4833B20A364BF06EE3BE3B9093EA4DF9	4	✅ Very playable. One known minor graphical glitch.
Super Turrican	33487D9A013F81F434323960203E564434F8D2F8	4	✅ No known issues.
Track and Field II	87E7943769CE95747AC80DA044B2CF9E63410AF2	1	✅ No known issues.
Tetris	FD9079CB5E8479EB06D93C2AE5175BFCE871746A	1	✅ No known issues.
WWF Wrestlemania	D55E8202929D922A84122921EF5C9671135B3E77	7	✅ No known issues.
Xenophobe	2C430A5D4AF069A4C4B9082422B7F570ADA5AE31	1	❌ Mostly unplayable. Tile corruption.

Implementation resources

For 6502 emulation:

• https://en.wikipedia.org/wiki/MOS_Technology_6502
• http://www.obelisk.me.uk/6502/reference.html
• http://archive.6502.org/books/mcs6500_family_programming_manual.pdf
• http://6502.org/documents/datasheets/mos/mos_6501-6505_mpu_preliminary_aug_1975.pdf

For NES internals:

• http://wiki.nesdev.com/w/index.php/NES_reference_guide