1-------------------------------------------------------------------------------- 2WHAT IS THIS? 3-------------------------------------------------------------------------------- 4This is DGen/SDL, a semi-fantastic emulator for Unix-esque operating systems 5supported by the Simple DirectMedia Layer (SDL) library. It produces a virtual 6environment in which Sega Genesis (MegaDrive outside the US) games may run 7with fairly accurate audio and video. 8 9-------------------------------------------------------------------------------- 10HOW DO I INSTALL IT? 11-------------------------------------------------------------------------------- 12You'll need SDL version 1.0 or greater. Fetch it from 13http://www.libsdl.org/, and install it. Make sure, if you're 14using prepackaged rpm's or deb's, to get both the SDL and SDL-devel packages. 15 16For Intel/AMD/Cyrix CPUs, you'll also need NASM, which can be found at 17http://www.web-sites.co.uk/nasm/, in order to utilize the assembler 18optimizations. *WARNING*: The NASM that comes prepackaged with RedHat 7.x is 19broken! Install the rpm from RedHat 6.x, and it should work. One such rpm can 20be found at http://pknet.com/~joe/nasm-0.98-2.i386.rpm. 21 22Now you should be able to build and install DGen like any other 23autoconf-using package: 24 25 sh ./configure && make && make install 26 27If you have egcs or GCC >= 2.95, you can give configure the '--with-extra-opt' 28switch, which will add some insane optimization to the CFLAGS used to compile 29the program, giving the binary a very decent speed boost. 30 31The control configuration and other options available in DGen/SDL are set 32through a file dgenrc, which should be in the location $HOME/.dgen/dgenrc. 33The sample.dgenrc file in this archive documents all the fields, and so does the 34dgenrc(5) manpage. If it doesn't exist, an empty one will be created when 35dgen is run. 36 37Now that it's been installed, running 'dgen ROMFILE' should run the Genesis 38program contained in ROMFILE. For a list of all the fancy options supported, 39run either 'dgen' with no options, or see the dgen(1) manpage for more detail. 40 41-------------------------------------------------------------------------------- 42IT'S TOO SLOW! 43-------------------------------------------------------------------------------- 44Well, sorry. Here are some ideas to help accelerate it: 45 46 - Lower the value of "int_nice" in your dgenrc. 0 is good for short tempers :-) 47 - Turn off sound. 48 - Run fullscreen, if possible. 49 - Increase int_soundsegs to 16 or (if you're desperate) 32. 50 - Buy a faster computer. (sorry, had to say it ;) 51 52-------------------------------------------------------------------------------- 53IT'S TOO FAST! 54-------------------------------------------------------------------------------- 55I couldn't believe it either, but someone asked me this. If you happen to find 56yourself in this unfortunate predicament, here's how to slow it down: 57 58 - Raise the sound rate to 44100Hz. It sounds a LOT better, and is a LOT slower. 59 - Increase the value of int_nice in your dgenrc. This is the best way to slow 60 things down, since it makes dgen much more CPU friendly. 61 - In the game, press the key set to 'dgen_cpu_toggle' (which defaults to F11), 62 to use the Musashi CPU core, which is slower and more accurate than 63 StarScream. 64 65-------------------------------------------------------------------------------- 66FREQUENTLY ASKED QUESTIONS 67-------------------------------------------------------------------------------- 68Q: DGen segfaults on startup! 69A: The two most common causes of this are a broken NASM, or an absent NASM. 70 RedHat 7.x distributions ship with a prepackaged NASM which doesn't work. 71 You'll need to use an RPM from a different distribution, or RedHat 6.x. 72 73Q: How do I set up OpenGL mode? 74A: OpenGL mode can be activated either from the commandline, or from the dgenrc 75 file. Using the '-G XxY' switch will activate OpenGL mode. The switch takes 76 the desired resolution as an argument. For example: 77 $ dgen -G 640x480 sonic.bin 78 will run with a 640x480 screen resolution. 79 80 So that you do not have to type this switch every time you use dgen, you 81 can add the following lines to ~/.dgen/dgenrc so that dgen will start in 82 OpenGL mode every time: 83 bool_opengl = yes 84 int_opengl_width = 640 85 int_opengl_height = 480 86 int_opengl_width and int_opengl_height can be changed to suit your own 87 preferences. 88 89Q: I make dgen setuid-root, and try to run it fullscreen, and all I get is 90 a black screen with the game running in the middle of it. 91A: You need to have your X server set up with a 320x240 video mode. For XFree86, 92 if you have XF86Setup installed (which is more than likely): 93 - Close all X sessions you have running. 94 - From a console, as root, run "XF86Setup". When asked "Would you like to use 95 the existing XF86Config file for defaults?" say Yes. 96 - After 30 seconds or so the X server should start in VGA mode, and put you 97 in the setup program. Everything else is set up, just click on the 98 "Modeselection" button in the top right-hand corner. 99 - From the list of possible modes, choose 1024x768 (or whatever mode you use 100 regularly), and 320x240 (which is the mode DGen wants). Choose a bits-per- 101 pixel from the list on the bottom (DGen works best in 15- or 16-bpp). 102 - Press "Done", then "Okay". 103 - It should restart the X server. When you see the message 104 "Congratulations!...", try pressing CTRL-ALT-KEYPAD+ to switch to your new 105 320x240 mode, just to make sure it works. Press CTRL-ALT-KEYPAD- to switch 106 back, and press "Save the configuration and exit". 107 - Restart your X session. If you use xdm, press CTRL-ALT-BACKSPACE to kill 108 the X server and restart it. Fullscreen should work now. 109 110Q: DGen's colors are messed up! 111A: Some video cards, such as most Riva cards, use different pixel formats 112 for true-color modes. If you use 16-bpp bit depth, try 15- or 32-bpp bit 113 depth. 114 115Q: I try compiling, but when I run ./configure, it tells me it can't find 116 sdl-config. I installed SDL from the rpm's. 117A: You need to install the SDL-devel rpm as well: 118 http://www.devolution.com/~slouken/SDL/release/SDL-devel-<version>-1.i386.rpm 119 120Q: Sonic 2 freezes right before the title screen! 121A: There is a bug in the StarScream CPU core which causes Sonic 2 to freeze 122 at this point. Press F11 to switch to the Musashi core, until you get to 123 the title sequence, then press it again to switch back to StarScream. Save 124 a snapshot here, so you don't have to go through it again. :) 125 126-------------------------------------------------------------------------------- 127BUGS 128-------------------------------------------------------------------------------- 129Of course the chances of finding a bug are unlikely, but if you do, tell me 130about it. Send me a patch too, if possible :-) Also, check the FAQ above before 131reporting bugs, to see if your question's already been answered. 132 133Enjoy DGen! 134