******* interNES ******* The Portable NES/Famicom Emulator version 0.2 (05/10/1996) based on the original code by Alex Krasivsky by Marat Fayzullin email: fms@freeflight.com IRC: RST38h WWW: http://www.freeflight.com/fms/ * DICLAIMERS * * Nintendo Entertainment System and Famicom are registered trademarks of Nintendo. * The author is in no way affiliated with Nintendo. * The author is in no way affiliated with any pirate group out there. * The author can not provide you with NES/Famicom games. * NEW IN THIS VERSION * * Some types of multi-paged cartridges work now. * A nasty CPU bug in LDX is fixed. * Battery-backed RAM support impemented. * INTRODUCTION * iNES is a portable emulator of the Nintendo Entertainment System (aka Famicom in Korea and Japan), written in C. The original code was written by Alex Krasivsky from Moscow. I added missing CPU commands, wrote screen drivers, and did some thorough hacking to make the emulator run about 70% of games. Given enough support, I hope to make it even more compatible with real NES in the future. You can always get the latest iNES binaries and support files from http://www.freeflight.com/fms/iNES/ Because of its portability, iNES can be compiled on a wide variety of platforms: Unix, Amiga, Macintosh, MSDOS, Windows, etc. Nevertheless, due to the nasty experience dealing with pirate wannabes of the Net after Virtual GameBoy emulator was released, I decided not to release the iNES source code, and not to create MSDOS and Windows versions of iNES at this moment. The only released version will be distributed in binary form for various flavors of Unix. I may also create a commercial version of iNES for Windows in the near future, but it will not have a demo version like Virtual GameBoy did. Sorry folks, send your thanks and fan mail to the person who cracked VGB demo and removed my name from "About" dialog box. If you wanna play with iNES, install Unix. If you want iNES-Windows and are willing to register ($35, the usual fee), let me know and I will count you. If you have any information on NES/Famicom, or the ROM-images which can be used for testing, and are willing to help, feel free to send mail to fms@freeflight.com. Any *intelligent* help is greatly appreciated :). * FOR OUR LEARNING-DISABLED READERS * #ifdef FLAME It is unnecessary to say, but for some people out there, let us repeat it: 1. I DO NOT HAVE ANY NINTENDO GAMES. 2. I DO NOT KNOW WHERE TO GET THEM. 3. I DO NOT KNOW WHERE TO GET A COPIER. 4. IT IS PIRACY TO DISTRIBUTE ROM-IMAGES OF NES/FAMICOM GAMES, AND PRETTY BAD ONE, AS THEY ARE STILL SOLD. Please, do not send me mail dealing with above-mentioned questions. #endif * WHAT IS INCLUDED * Following files are included into the distribution: ines - iNES executable file [ines -help for options] dasm - Little 6502 disassembler iNES.doc - This documentation CART.NES - Sample cartridge which contains a testing program for NES CART.ASM - The source code of a testing program * BUTTONS/OPTIONS/ETC. * iNES is controlled by following buttons: [SPACE] - A button (also: A,S,D,F,G,H,J,K,L) [LALT] - B button (also: Z,X,C,V,B,N,M) [TAB] - SELECT button [ENTER] - START button [ESC] - Quit emulation [SHIFT] and [CAPSLOCK] switch between joypads. When compiled with #define DEBUG: [F1] - Turn tracing on/off [F2] - Shift ChrTab down by $0400 [F3] - Shift ChrTab up by $0400 [F4] - Shift ChrGen down by $1000 [F5] - Shift ChrGen up by $1000 [F6] - Show LCD controller registers [F7] - Show sprite attributes iNES can be started with following options: Usage: ines [-option1 [-option2...]] = name of file to load as cartridge [CART.NES] [-option] = -verbose - Select debugging messages [5] 0 - Silent 1 - Startup messages 2 - Illegal writes 4 - Illegal CPU ops 8 - Bank switching -vperiod - Set VBlank interrupts period [10000ops] -uperiod - Number of interrupts per screen update [2] -help - Print this help page -shm/-noshm - Use/don't use MIT SHM extensions for X [-shm] -saver/-nosaver - Save/don't save CPU when inactive [-saver] When compiled with #define DEBUG: -trap
- Trap execution when PC reaches address [FFFFh] * CARTRIDGE FILE FORMAT * The iNES distribution includes a single cartridge image with a program allowing to test the emulator. There is also a source code of this program included. Following is the format of ROM-image files used by iNES (.NES extension): byte contents ------------------------------------------------------------------------- 0-3 String "NES^Z" 4 Number of 16kB ROM banks 5 Number of 8kB VROM banks 6 bit 0 1 for vertical mirroring, 0 for horizontal mirroring bit 1 1 for battery-backed RAM at $6000-$7FFF bit 2-3 Reserved bit 4-7 Type of ROM bank selector 0 - None 1 - Megaman2,Bomberman2,Destiny,etc. 2 - Castlevania,LifeForce,etc. 15 - 100-in-1 cartridge (experimental) 7-15 Reserved 16-... ROM banks, in ascending order ...-EOF VROM banks, in ascending order ------------------------------------------------------------------------- Note that this format will most likely change in the next version of iNES, therefore do not take it for something permanent. The general structure will stay the same though. The Vertical/Horizontal Mirroring flag requires an additional explanation. In the real NES/Famicom cartridges, either A10 or A11 line of the address bus can be connected. Depending on it, video memory may either contain two screens at addresses $2000/$2400 mirrored at $2800/$2C00 (Vertical Mirroring), or two screens at $2000/$2800 mirrored at $2400/$2C00 (Horizontal Mirroring). The games which only use one screen do not care about the mirroring. The games using two screens require an appropriate mirroring though. --------------- Marat Fayzullin