================================================================= genecyst Version 0.32 (09/27/97) by Bloodlust Software ================================================================= Do not send any files without asking first. Do not ask about SNESticle (or anything else you want emulated). I realize that the FM emulation is pretty bad, but since I dont have a (working) Genesis anymore I'm going mainly from memory and my tonedeaf ears. The envelope rates, detune, and relative volumes need to be tweaked heavily. Most games sound better if you turn up the bass on your soundcard. The CPU skipper analyzes 68k execution and dynamically modifies the ROM code to prevent idle loops and other slow things. This can almost halve the time taken to emulate the 68k cpu in most games. It is by default off because there's a small chance that it may introduce a compatibility problem. Racing games appear to work better now but they desperately need a true line by line graphics engine to be 100% accurate and to be rendered faster. Patience. DMAfix on Rockman prevents those evil dots. --------------------- What it is --------------------- genecyst is a DOS based emulator for the Sega Genesis. The 68K, Z80, DAC, digital FM emulation and graphics rendering were written from *scratch* in assembly. The rest is in C++. It is freeware and it is not to be distributed with game ROMs and it is not to be modified or sold. Loads roms in the BIN, SMD or split (*.1) file formats. OS/2 users: -disablelfn --------------------- Revisions --------------------- Version 0.32: -Fixed relative path problem on command line -Autoversion setting -Fixed FM channel 6 problem -Improved CPU skipper -Corrected 68K IRQ levels (stupid typo) -Fixed a Z80 reset bug -Fixed some more z80 bugs -F11/F12 switch resolutions (get SDD!) Version 0.31: -Fixed a VRAM fill bug -'-exclusive' command line option (disables windows multitasking) -Fixed some DAC lag -Altered the way envelopes are handled -Dynamic CPU skipper -Improved H-ints (Gunstar intro, S.Showdown, Chuck Rock, Timekillers, racing games) -Louder PSG -LFO amplitude modulation -PSG noise channel (forgot about that) -Altered HV counter -Fixed minor z80 bug -Fixed minor soundlogging bug Version 0.30: -Encapsulated gui.vol -DMA transfers now eat clock cycles -Better LFN detection -Raster based effects (see below) -Sprite masking -Correct sprite priorities -Rendering optimizations -Z80 rewritten -Speed throttle disabling -'Force display enable' option added (see below) -Wave output logging added -Digital YM2612 FM synthesis -Most of 68k emulation rewritten -Cell based V-scrolling -Split cart format support -State display -'DMAfix' prevents vram writes during DMA transfers -Digital PSG emulation -Faster DMA transfers -Accurate HVcounter -'version' command line option -Scanlines in mode 256x256 -Correct window placement/priority -Romdir saved -CRAM reads -Changed z80 busreq -Fixed SSP/USP problem with state restores -68K: Added BTST Dx,# instruction -68K: Fixed STOP instruction -Fixed joystick calibration -Small font added -Z80 speedup Version 0.20: -Highly accurate profiling with RDTSC (pentium only) -Faster FPU mem->vid copy (pentium only) -Automatic 6-button joystick disabling -68K: LineA/F emulation -68K: Corrected USP/SSP -YM2612 FM emulation -RAM->VRAM DMA transfer bug fixed -DAC sound output -Save state file format changed (this was unavoidable) -Z80 emulation (buggy) Version 0.14: -Unchained modeX modes added (320x240 and 320x224) These modes are considerably slower than VESA modes so don't use them -6 button joystick inputs (almost) -Stop intruction fixed -Fixed MOVE->CCR data size -Sped up 68k branching -Funky Z-flag implemented -Improved waitvsync -Pattern table viewer -Layer enabling dialog -Fixed DOS hardware error handler -Readjusted window priority Version 0.13: -PCX palette saving fixed -Fixed MOVEM wraparound bug -Fixed 68k flag bugs -Added primitive Z80 faking -Altered Window priority -ROM checksum fixer (fixes games that "red screen") Version 0.12: -Initial release --------------------- What it does --------------------- What is emulated: -68000 CPU @ 8Mhz -Z80 secondary CPU @ 4Mhz -DAC output -YM2612 FM synthesis -TI76489 PSG -VDP -DMA -ScrollA/ScrollB/Sprites/Window -Some raster effects -H/V interrupts -Dual 4-button/7-button joypad emulation -US/Japan/Europe variants Other neat features: -Multiple save states and battery backed ram -Joystick support -VESA support -Save .pcx snapshots -Game genie codes -Rom checksum fixer -Wave output logging --------------------- What it lacks --------------------- Digital FM emulation needs much work Stereo FM (probably not worth it) Graphic equalizer 68000 emulation is still buggy Z80 emulation still buggy H-ints aren't emulated correctly I dont think Shadow/highlighting effects Interlaced modes Netplay Many games do not work correctly (or at all). Dont bother me if a ROM doesn't work. --------------------- What you need --------------------- A Pentium with at least 8MB of RAM. genecyst can take advantage of VESA 2.0 support if it exists. If it does not exist, genecyst will resort to only the video modes 320x200, 256x224, 256x240, 256x256, 320x224, 320x240. The last 2 modes are planar (unchained) ModeX modes, meaning that they are not linear and are very SLOW. Get a VESA extender such as Scitech Display Doctor (www.scitechsoft.com) and use 320x240 instead. --------------------- Work it baby --------------------- Use alt- to access the menu options (ie alt-l loads) The default keys for the first controller are ABC='zxc', Start='v', XYZ='asd', and the arrow keys. They can be remapped from the Settings/Input device menu. Enter/Tab will simulate Start/C on controller 1 if you have a 2 button joystick, ONLY when the GUI is disabled or the game window has input focus (click on it) 6-button Genesis controllers can be enabled from the Settings menu. Having a 6-button controller enabled on older games will most likely cause them to go haywire. The emulation of the 6-button controllers is only a guess, but it seems to work for most games. Most games need to be reset if you change from 3 to 6 buttons. 6-button support will be automatically disabled for games which don't support them as specified in their ROM header. Some carts check to see what version of hardware they are running on (US/Japan/Europe), and they'll bitch if played on the wrong system. The setting in the Version menu is the default hardware preference. With Auto-Version on, if the default version isn't listed in the ROM header, the version will be automatically changed. Some games contain battery backed RAM. This RAM is automatically loaded and saved to "xxxx.GSV" files. F5/F7 saves and loads states. Pressing the keyboard keys 0-9 (not the numeric keypad ones) will change the current state slot for subsequent saves/loads. The state filename follows the form "xxxx.GS?" where 'xxxx' is the romname and ? is the current save slot (0-9). Know that the battery backed RAM is saved in each state file. The battery RAM from any state file that is loaded will overwrite the ROM's .GSV file. "Raster effects" refers to changes to the display made during a frame. Many games use H-interrupts to change video registers and change the screen output as it is being drawn. H-ints are automatically enabled with raster effects on. Raster effect emulation is by default off because its still a bit buggy. For most games there will be little speed difference with or without raster effects, however some games change the video registers many times per frame. Games that do that will slow down a lot with raster effects on. Palette-based raster effects aren't emulated yet, but they are used quite frequently. Also, the raster effects will not persist with the cpu paused. These problems will be remedied in later versions. Examples of games that benefit from raster effects are TJ&E,G&G, sf2turbo, and Landstalker. Some games create a letterbox effect by turning the display enable bit off near the bottom of the screen (usually after a H-interrupt). The 'force display enable' menu option will display the screen regardless of the status of this bit. This is only needed for a few games, and only if you choose to leave raster effects off. The DMAfix option prevents writes to the VDP during DMA transfers (fixes Superhydlide). --------------------- Sound --------------------- Genesis sound output is driven by a secondary Z80 processor running at 4Mhz, however the 68000 can also control the sound hardware directly. The Genesis uses a YM2612 sound chip which has six FM channels and one digital channel. A fast Pentium is highly recommended for decent sound emulation. You can change the sample rate from its default of 22050hz with the -SNDRATE command line option (or just edit gen.ini). The lesser the sample rate the less cpu time needed to generate the FM sound. 44100hz sounds very clear but really is overkill. Sometimes lower sampling rates sound better. Z80 emulation can be toggled from the CPU menu. Disabling the Z80 will speed up the overall emulation, but sound will be absent in most games. If a ROM stops due to a Z80 invalid opcode, remember that the Z80 emulation is buggy and incomplete. Disable Z80 and reset. Z80 faking can be toggled from the CPU menu. It is workaround that will fool the 68000 into thinking that a Z80 is actually present and running. Some games loop waiting for the Z80 to respond. All sound can be disabled with the -nosound command line option. Z80 emulation can be disabled with the -disablez80 command line option. --------------------- Input --------------------- genecyst supports analog joysticks, 4-button gamepads, 6-button gamepads, the Gravis GrIP gameport and keyboard input. - There are two input devices, one each for controller 1 and 2. - Change the input devices with Settings/RedefineInput - Enter/Tab will simulate Start/C on controller 1, ONLY when the GUI is disabled or the game window has input focus (click on it) - You can remap the buttons for a joystick input device with the command line option '-remapbut' or from the "Remap buttons" dialog... Simply click on the button type and then press the joystick button you wish to use. Pressing any key will set the NES button to "None". - You can redefine the keys for a Keyboard input device with the Redefine Keys dialog, or with the '-setkey' command line option - Joystick 1 or 2 refer to 2-button analog joysticks only! - You can interactively calibrate the joystick with the "Calibrate" button. Just center and swirl. The joystick thresholds can be also set with the '-joythresh' command line option. - The '-analogjoyres' command line option sets the maximum number of times that the joystick port is polled (usually this need not be changed) - In order to enable GrIP support, you MUST copy the "grip.gll" file to the startup directory. genecyst will load the driver if it finds it and the GrIP devices in slot 1 or 2 can be used. Note that if you have Win95 GrIP drivers installed it may not be possible for a DOS application to access the GrIP port. Information on reading the MS Sidewinder gamepad in its native digital mode under DOS would be nice. Microsoft is uncooperative. --------------------- Timing --------------------- You can adjust the timing from the Settings menu. HBlank inst is the number of instructions per scanline (224 lines per frame). VBlank inst is the number of instructions per vertical retrace (vblank). Vfps is the number of emulated frames per second. Some games require more instructions per frame in order to not slowdown. In other words some games need more CPU power. Other games may need less. An example of this is Gauntlet4 which needs at least 3000 Vblankinst (as well as h-ints on). The more time spent emulating the 68k, the less time available to render frames and vice versa. --------------------- ROM patching --------------------- genecyst supports GameGenie codes and general patching of the CPU ROM address space (0-3FFFFE) at even addresses. Bring up the ROM patching dialog with F6 or from the CPU menu. There are two edit fields in the dialog, the Name and the Code. The Code field is where the actual code goes (eg SCRA-BJX0). The Name field lets you type in a description of the code (eg "Rings worth 2"), if no name is entered then the code string is used as the name. Once you've filled these in, clicking "Add" (or pressing enter) will add it to the list of patches. To activate or deactivate the patch, doubleclick on the code name in the listbox or click on "Toggle". "Remove" deletes the patch completely. "Save" writes all the patches to the text file .pat, this file is decribed below. genecyst accepts either GameGenie codes or raw patches. GameGenie codes are 8 digits long and use the symbols: ABCDEFGHJKLMNPRSTVWXYZ0123456789 The use of a '-' is optional. The raw patches are in the format: <$addr>:<$val> <$addr> is the 24-bit hex address (must be even) <$val> is the 16-bit hex value to be patched at that address. genecyst can save a .pat file that contains all the patches created during a game. This file can be modified using a text editor. Each line of the .pat file looks like this: [] is the patch itself (GG or raw format). is the text description of the code, if no name is supplied then the code is used as the name Note: If more than one patch modifies the same address then only one can be active at once. Activating one will deactivate the others. Another Note: Most Genesis games do a rom checksum in order to verify their integrity. Therefore, having a patch active during the ROM's startup code could in most cases cause the ROM to crash itself. (Hence the use of so called 'master codes') --------------------- Command line options --------------------- @ : Parses the file for command line options -res : Sets the resolution to xw,yw on startup. -setinput : Sets input device to -remapbut : Remaps buttons for : can be JOY1, JOY2, GRAVIS, GRIP1, GRIP2, 6BUTTON -setkey