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FCE Ultra General Documentation

Last updated November 12, 2003
Valid as of FCE Ultra 0.97

Table of Contents:


Introduction

FCE Ultra is an NTSC and PAL Famicom/NES emulator for various platforms. It is based upon Bero's original FCE source code. Current features include good PPU, CPU, pAPU, expansion chip, and joystick emulation. Also a feature unique to this emulator(at the current time) is authentic Game Genie emulation. Save states and snapshot features also have been implemented.

This document has been arranged to keep user interface details and emulation details as separate as possible, though this has not been accomplished entirely.

In several places references are made to the "base directory". If you are running a port on a UN*X-like system(Linux/*BSD/Mac OSX/SunOS/etc.), the base directory is "~/.fceultra", or in other words, "your home directory plus .fceultra". For all other ports(including DOS and MS Windows), the base directory is the directory that the executable is in.

History of FCE Ultra

This section is a work-in-progress. Some details may be incorrect.
Bero originally wrote a NES emulator that was referred to as FCE. This name was apparently meant only to serve as a temporary name, but its usage remained. Xodnizel originally ported it to Linux SVGAlib, and made a few improvements. This code base was abandoned, and work began anew, under DOS, with the original FCE source code. At the end of November, 1998, FCE Ultra Beta 1 was released.

FCE Ultra remained DOS-only until version 0.18, when it was ported to Linux SVGAlib, and released as a staticly-linked executable. The first MS Windows port was released as version 0.25.

The source code of 0.40 was released on November 12, 2000. It retained the simple license of FCE for a long time, which stated that " This software is freeware.you can use it non-commercially." Almost two years later, in June 2002, 0.80 was released, and FCE Ultra was relicensed under the GNU GPL.


Core Features

CPU

All official instructions of the NES' CPU, the 2A03, which is compatible(mostly) with the 6502, are emulated. "Unofficial" instructions are also emulated, though probably not as accurately as the more well-defined official instructions.


PPU

Palettes

FCE Ultra has many palette features, including loading a custom palette to replace the default NES palette. The palette from an NTSC NES can also be generated on-the-fly.

First, a note on on the format of external palettes; Palette files are expected to contain 64 8-bit RGB triplets(each in that order; red comes first in the triplet in the file, then green, then blue). Each 8-bit value represents brightness for that particular color. 0 is minimum, 255 is maximum.

Palettes can be set on a per-game basis. To do this, put a palette file in the "gameinfo" directory with the same base filename as the game you wish to associate with and add the extension "pal". Examples:

        
                File name:              Palette file name:
                 BigBad.nes              BigBad.pal
                 BigBad.zip              BigBad.pal
                 BigBad.Better.nes       BigBad.Better.pal
	

With so many ways to choose a palette, figuring out which one will be active may be difficult. Here's a list of what palettes will be used, in order from highest priority to least priority(if a condition doesn't exist for a higher priority palette, the emulator will continue down its list of palettes).


Sound

All 5 internal sound channels are supported(2x rectangle, triangle, noise, and DMC/PCM). Sound channels are emulated with CPU instruction granularity. There are two sound quality options. Low-quality sound, the default sound quality option, generates sound data at 16x the playback rate and averages those samples together to 1 sample. This method works fairly well and is reasonably fast, but there is still some aliasing and sound distortion. All sample rates between 8192Hz and 96000Hz are supported.

The high-quality sound emulation is much more CPU intensive, but the quality is worth it, if your machine is fast enough. Sound data is generated at the NES' CPU clock rate(about 1.8MHz for the NTSC NES), and then resampled to the output sample rate. Custom-designed 483rd order Parks-McClellan algorithm filter coefficients are used. Supported playback rates are 44100Hz, 48000Hz, and 96000Hz. The following filter statistics apply for NTSC emulation.

Rate:Passband Upper Bound(Hz):Passband ripple(dB):Transition bandwidth(Hz):Stopband attenuation(dB):
4410011982.50.2010067.566.4
4800013932.50.1010067.560.0
9600030000.00.0118000.0103.0

In addition to improved tonal quality, the high-quality sound emulation also simulates deficiencies present in the NES' D/A converter, which causes the sound output to be non-linear(for example, 16+16 might create an output equivalent to 25). Emulation of this is necessary for the DMC/PCM sound channel to sound correct. For example, without this feature, the drums in "Crystalis" are excessively fuzzy.

The "highest" sound quality mode is similar to the normal high-quality mode, but the filters are of a higher order(1024 coefficients). Ripple is reduced, the upper bound of the passband is higher, and the stopband attenuation is slightly higher. The highest-quality mode filter coefficients were created using "gmeteor". The parameters used to create these filters can be found in the source code distribution.

Besides the 5 internal NES sound channels, FCE Ultra emulates the extra sound capabilities of the Konami VRCVI, Konami VRCVII, Namco 106, Nintendo MMC5, and the Sunsoft FME-07 chips. The extra sound channel in the Famicom Disk System is also emulated, but the support for its FM capabilities is limited.


Input

FCE Ultra emulates the standard NES gamepad, the Four-Score multiplayer adapter, the Zapper, the Power Pad, and the Arkanoid controller. The Famicom version of the Arkanoid controller, the "Space Shadow" gun, the Famicom 4-player adapter, and the Family Keyboard are also emulated.

Zapper

Most Zapper NES games expect the Zapper to be plugged into port 2. and most VS Unisystem games expect the Zapper to be plugged into port 1.

The left mouse button is the emulated trigger button for the Zapper. The right mouse button is also emulated as the trigger, but as long as you have the right mouse button held down, no color detection will take place, which is effectively like pulling the trigger while the Zapper is pointed away from the television screen. Note that you must hold the right button down for a short time to have the desired effect.


File Formats/Expansion Hardware

FCE Ultra supports the iNES, FDS(raw and with a header), UNIF, and NSF file formats. FDS ROM images in the iNES format are not supported; it would be silly to do so and storing them in that format is nonsensical.

FCE Ultra supports loading ROM/disk images from some types of compressed files. FCE Ultra can load data from both PKZIP-format files and gzip-format files. Only the "deflate" algorithm is supported, but this is the most widely used algorithm for these formats. A compressed FDS disk image will only be saved back to disk if it uses the gzip format.

All files in a PKZIP format archive will be scanned for the followings extensions: .nes, .fds, .nsf, .unf, .nez, .unif The first compressed file to have one of these extensions will be loaded. If no compressed file has one of these extensions, the first compressed file will be loaded.

iNES Format

The battery-backed RAM, vertical/horizontal mirroring, four-screen name table layout, and 8-bit mapper number capabilities of the iNES format are supported. The 512-byte trainer capability is also supported, but it is deprecated. Common header corruption conditions are cleaned(let's go on a DiskDude hunt), though not all conditions can be automatically detected and fixed. In addition, a few common header inaccuracies for games are also corrected(detected by CRC32 value). Note that these fixes are not written back to the storage medium.

Support for the recent VS System bit and "number of 8kB RAM banks" is not implemented. Too many iNES headers are corrupt where this new data is stored, causing problems for those games.

The following table lists iNES-format "mappers" supported well in FCE Ultra.

Number:Description:Game Examples:
0No bankswitchingDonkey Kong, Mario Bros
1Nintendo MMC1MegaMan 2, Final Fantasy
2Simple 16KB PROM Switch(UNROM)MegaMan, Archon, 1944
3Simple 8KB VROM Switch(CNROM)Spy Hunter, Gradius
4Nintendo MMC3Super Mario Bros. 3, Recca, Final Fantasy 3
5Nintendo MMC5Castlevania 3, Just Breed, Bandit Kings of Ancient China
6FFE F4 Series(hacked, bootleg)
7AOROMBattle Toads, Time Lord
8FFE F3 Series(hacked, bootleg)
9Nintendo MMC2Punchout!
10Nintendo MMC4Fire Emblem, Fire Emblem Gaiden
11Color DreamsCrystal Mines, Bible Adventures
12??Dragon Ball Z 5 ("bootleg" original)
13CPROMVideomation
15Multi-cart(bootleg)100-in-1: Contra Function 16
16Bandai ??Dragon Ball Z, SD Gundam Gaiden
17FFE F8 Series(hacked, bootleg)
18Jaleco SS806Pizza Pop, Plasma Ball
19Namco 106Splatter House, Mappy Kids
21Konami VRC4 2AWaiWai World 2, Ganbare Goemon Gaiden 2
22Konami VRC4 1BTwinbee 3
23Konami VRC2BWaiWai World, Crisis Force
24Konami VRC6Akumajou Densetsu
25Konami VRC4Gradius 2, Bio Miracle:Boku tte Upa
26Konami VRC6 A0-A1 SwapEsper Dream 2, Madara
32IREM G-101Image Fight 2, Perman
33Taito TC0190/TC0350Don Doko Don
34NINA-001 and BNROMImpossible Mission 2, Deadly Towers, Bug Honey
40(bootleg)Super Mario Bros. 2
41Caltron 6-in-1Caltron 6-in-1
42(bootleg)Mario Baby
44Multi-cart(bootleg)Super HiK 7 in 1
45Multi-cart(bootleg)Super 1000000 in 1
46Game StationRumble Station
47NES-QJNintendo World Cup/Super Spike V-Ball
48Taito TC190VFlintstones
49Multi-cart(bootleg)Super HiK 4 in 1
50(bootleg)Super Mario Bros. 2
51Multi-cart(bootleg)11 in 1 Ball Games
52Multi-cart(bootleg)Mario Party 7 in 1
57Multi-cart(bootleg)Game Star GK-54
60Multi-cart(bootleg)4 in 1(Reset-selected)
61Multi-cart(bootleg)20 in 1
62Multi-cart(bootleg)Super 700 in 1
64Tengen RAMBO 1Klax, Rolling Thunder, Skull and Crossbones
65IREM H-3001Daiku no Gensan 2
66GNROMSMB/Duck Hunt
67Sunsoft ??Fantasy Zone 2
68Sunsoft ??After Burner 2, Nantetta Baseball
69Sunsoft FME-7Batman: Return of the Joker, Hebereke
70??Kamen Rider Club
71CamericaFire Hawk, Linus Spacehead
72Jaleco ??Pinball Quest
73Konami VRC3Salamander
74Taiwanese MMC3 CHR ROM w/ VRAMSuper Robot Wars 2
75Jaleco SS8805/Konami VRC1Tetsuwan Atom, King Kong 2
76Namco 109Megami Tensei
77IREM ??Napoleon Senki
78Irem 74HC161/32Holy Diver
79NINA-06/NINA-03F15 City War, Krazy Kreatures, Tiles of Fate
80Taito X-005Minelvation Saga
82Taito ??Kyuukyoku Harikiri Stadium - Heisei Gannen Ban
83Multi-cart(bootleg)Dragon Ball Party
85Konami VRC7Lagrange Point
86Jaleco ??More Pro Baseball
87??Argus
88Namco 118Dragon Spirit
89Sunsoft ??Mito Koumon
90??Super Mario World
91??Mari Street Fighter 3 Turbo
92Jaleco ??MOERO Pro Soccer
93??Fantasy Zone
94??Senjou no Ookami
95Namco ??Dragon Buster
96Bandai ??Oeka Kids
97??Kaiketsu Yanchamaru
99VS System 8KB VROM SwitchVS SMB, VS Excite Bike
105NES-EVENTNintendo World Championships
107??Magic Dragon
112AsderSango Fighter, Hwang Di
113MB-91Deathbots
114??The Lion King
115??Yuu Yuu Hakusho Final
117??San Guo Zhi 4
118MMC3-TLSROM/TKSROM BoardYs 3, Goal! 2, NES Play Action Football
119MMC3-TQROM BoardHigh Speed, Pin*Bot
140Jaleco ??Bio Senshi Dan
144??Death Race
151Konami VS System ExpansionVS The Goonies, VS Gradius
152??Arkanoid 2, Saint Seiya Ougon Densetsu
153Bandai ??Famicom Jump 2
154Namco ??Devil Man
155MMC1 w/o normal WRAM disableThe Money Game, Tatakae!! Rahmen Man
156??(TBA)
158RAMBO 1 DerivativeAlien Syndrome
180??Crazy Climber
182??Super Donkey Kong
184??Wing of Madoola, The
189??Thunder Warrior, Street Fighter 2 (Yoko)
193Mega SoftFighting Hero
200Multi-cart(bootleg)1200-in-1
201Multi-cart(bootleg)21-in-1
202Multi-cart(bootleg)150 in 1
203Multi-cart(bootleg)35 in 1
225Multi-cart(bootleg)58-in-1/110-in-1/52 Games
226Multi-cart(bootleg)76-in-1
227Multi-cart(bootleg)1200-in-1
228Action 52Action 52, Cheetahmen 2
229Multi-cart(bootleg)31-in-1
230Multi-cart(bootleg)22 Games
231Multi-cart(bootleg)20-in-1
232BIC-48Quattro Arcade, Quattro Sports
234Multi-cart ??Maxi-15
235Multi-cart(bootleg)Golden Game 150 in 1
240??Gen Ke Le Zhuan, Shen Huo Le Zhuan
242??Wai Xing Zhan Shi
244??Decathalon
246??Fong Shen Ban
248??Bao Qing Tian
249Waixing ????
250??Time Diver Avenger

UNIF

FCE Ultra supports the following UNIF boards. The prefixes HVC-, NES-, BTL-, and BMC- are omitted, since they are currently ignored in FCE Ultra's UNIF loader.

Group:
Name:Game Examples:
Bootleg:
MARIO1-MALEE2Super Mario Bros. Malee 2
NovelDiamond9999999in1Novel Diamond 999999 in 1
Super24in1SC03Super 24 in 1
Supervision16in1Supervision 16-in-1
Unlicensed:
Sachen-8259ASuper Cartridge Version 1
Sachen-8259BSilver Eagle
Sachen-74LS374NAuto Upturn
SA-016-1MMaster Chu and the Drunkard Hu
SA-72007Sidewinder
SA-72008Jovial Race
SA-0036Mahjong 16
SA-0037Mahjong Trap
TC-U01-1.5MChallenge of the Dragon
8237Pocahontas Part 2
MMC1:
SAROMDragon Warrior
SBROMDance Aerobics
SCROMOrb 3D
SEROMBoulderdash
SGROMDefender of the Crown
SKROMDungeon Magic
SLROMCastlevania 2
SL1ROMSky Shark
SNROMShingen the Ruler
SOROMNobunaga's Ambition
MMC3:
TFROMLegacy of the Wizard
TGROMMegaman 4
TKROMKirby's Adventure
TKSROMYs 3
TLROMSuper Spike V'Ball
TLSROMGoal! 2
TR1ROMGauntlet
TQROMPinbot
TSROMSuper Mario Bros. 3
TVROMRad Racer 2
MMC5:
EKROMGemfire
ELROMCastlevania 3
ETROMNobunaga's Ambition 2
EWROMRomance of the Three Kingdoms 2
MMC6:
HKROMStar Tropics
Nintendo Discrete Logic:
CNROMGotcha
CPROMVideomation
GNROMSuper Mario Bros./Duck Hunt
MHROM
NROM-128Mario Bros.
NROM-256Super Mario Bros.
RROM-128
UNROMMegaman

Famicom Disk System

You will need the FDS BIOS ROM image in the base FCE Ultra directory. It must be named "disksys.rom". FCE Ultra will not load FDS games without this file.

Two types of FDS disk images are supported: disk images with the FWNES-style header, and disk images with no header. The number of sides on headerless disk images is calculated by the total file size, so don't put extraneous data at the end of the file.

You should make backups of all of your FDS games you use with FCE Ultra. This is because FCE Ultra will write the disk image back to the storage medium, and the disk image in RAM might have been corrupted because of inaccurate emulation(this case is not likely to occur, but it could occur).

Game Genie

The Game Genie ROM image is loaded from the file "gg.rom" in the base directory the first time Game Genie emulation is enabled and a ROM image is loaded since the time FCE Ultra has run.

The ROM image may either be the 24592 byte iNES-format image, or the 4352 raw ROM image.

Remember that enabling/disabling Game Genie emulation will not take effect until a new game is loaded(this statement shouldn't concern any of the "run once" command-line driven ports).

VS Unisystem

FCE Ultra currently only supports VS Unisystem ROM images in the iNES format. DIP switches and coin insertion are both emulated. The following games are supported, and have palettes provided(though not necessarily 100% accurate or complete):

Automatic IPS Patching

Place the IPS file in the same directory as the file to load, and name it filename.ips.

        Examples:       Boat.nes - Boat.nes.ips
                        Boat.zip - Boat.zip.ips
                        Boat.nes.gz - Boat.nes.gz.ips
                        Boat     - Boat.ips
        

Some operating systems and environments will hide file extensions. Keep this in mind if you are having trouble.

Patching is supported for all supported formats(iNES, FDS, UNIF, and NSF), but it will probably only be useful for the iNES format. It can be used with the FDS format, but be warned that it will permanently patch your disk image, as the disk image is written back to disk when the game is unloaded(unless the disk image is in a zip file, in which case it isn't written back to disk). UNIF files can't be patched well with the IPS format because they are chunk-based with no fixed offsets.


Using FCE Ultra

Key Assignments

Key:Action:
F5Save state.
F7Load state.
0-9Select save state slot.
F9Save screen snapshot.
F10Reset.
F11Hard reset(toggle power switch).
F12Exit.

VS Unisystem

Key:Action:
F8Insert coin.
F6Show/Hide dip switches.
1-8Toggle dip switches(when dip switches are shown).

Famicom Disk System

Key:Action:
F6Select disk and disk side.
F8Eject or Insert disk.

Game Pad

Key:Button on Emulated Gamepad:
Left ControlB
Left AltA
Enter/ReturnStart
TabSelect
Cursor DownDown
Cursor UpUp
Cursor LeftLeft
Cursor RightRight

Power Pad

Side B
OP []
KL;'
M,./

Side A
P [
KL;'
,.

Family Keyboard

All emulated keys are mapped to the closest open key on the PC keyboard, with a few exceptions. The emulated "@" key is mapped to the "`"(grave) key, and the emulated "kana" key is mapped to the "Insert" key(in the 3x2 key block above the cursor keys).

To enable or disable Family Keyboard input, press the "Scroll Lock" key. When Family Keyboard input is enabled, FCE Ultra will also attempt to prevent any key presses from being passed to the GUI or system.

Command-line

FCE Ultra supports arguments passed on the command line. The MS Windows port only allows for a file name to be specified, however. Arguments are taken in the form of "--parameter value". Windows users use only one dash: "-parameter value". Some arguments are valueless. Arguments that have both a parameter and a value will be saved in the configuration file, with the exception being the network-play arguments. All ports other than the MS Windows one recognize the following parameters:

Argument:Value Type:Default value:Description:
--cpalette xstring0Load a custom global palette from file "x". Specifying "0" will cause FCE Ultra to stop using the custom global palette.
--ntsccol xboolean0If value is true, enable automatic generation and use of an NTSC NES' colors.
--pal xboolean0If value is true, emulate a PAL NES. Otherwise emulate an NTSC NES.
--sound xinteger48000(44100 for DOS)Sets the playback rate. If it is zero, sound emulation(and output) is disabled.
--soundvol xinteger100Sound volume.
--soundq xboolean0If value is true, enable high-quality sound emulation.
--input1 x
and
-input2 x
stringgamepadSelect input device for input port 1 or 2. Valid strings are "none", "gamepad", "zapper", "powerpada", and "powerpadb".
--fcexp xstringnoneSelect Famicom expansion port device. Valid strings are "none", "shadow", "arkanoid", "4player", and "fkb".
--nofs xboolean0If value is true, disable four-score emulation.
--ggboolean0Enable Game Genie emulation.
--subase xboolean0If value is true, Save extra game data files under the base directory.
--snapname xboolean0If value is true, use an alternate naming scheme(file base and numeric) for screen snapshots.
--nothrottle xboolean0If value is true, disable the speed throttling that is used when sound emulation is disabled.
--clipsides xboolean0If value is true, clip leftmost and rightmost 8 columns of pixels of the video output.
--slstart xinteger8First scanline to be rendered in NTSC emulation mode(when PAL emulation is disabled).
--slend xinteger231Last scanline to be rendered in NTSC emulation mode.
--slstartp xinteger0First scanline to be rendered in PAL emulation mode.
--slendp xinteger239Last scanline to be rendered in PAL emulation mode.

SDL

Argument:Value Type:Default value:Description:
--joyx yinteger,integer0Enable joystick #y for virtual joystick #x(both starting at "1").
--stretchx/-stretchy xboolean0/0Stretch to fill surface on x or y axis(fullscreen, only with OpenGL).
--fsboolean0Full screen mode.

DOS

Linux SVGAlib


Credits

Name:Contribution(s):
\Firebug\High-level mapper information.
BeroOriginal FCE source code.
Brad TaylorNES sound information.
Chris HickmanArchaic Ruins.
Donald MooreDC PasoFami NES packs.
Fredrik OlsonNES four-player adapter information.
Gilles VollantPKZIP file loading functions.
gorohVarious documents.
Info-ZIPZLIB
Jeremy ChadwickGeneral NES information.
Justin SmithGood stuff.
Kevin HortonLow-level NES information and sound information.
KiVarious technical information.
Mark KnibbsVarious NES information.
Marat FayzullinGeneral NES information.
Matthew ConteSound information.
noriFDS sound information.
QuietustVRC7 sound translation code by The Quietust (quietust at ircN dort org).
R. HoelscherFamicom four-player adapter information.
Rob MoccaDC PasoFami NES packs, testing.
Sean WhalenNode 99
Tatsuyuki SatohOPL2 emulator used for the VRCVII sound emulation.
TheRedEyeROM images, testing.