mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-09-17 11:54:50 +02:00
28775cc3aa
---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup. [Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup.
86 lines
3.6 KiB
C
86 lines
3.6 KiB
C
/***************************************************************************************
|
|
* Genesis Plus
|
|
* Mega CD / Sega CD hardware
|
|
*
|
|
* Copyright (C) 2012 Eke-Eke (Genesis Plus GX)
|
|
*
|
|
* Redistribution and use of this code or any derivative works are permitted
|
|
* provided that the following conditions are met:
|
|
*
|
|
* - Redistributions may not be sold, nor may they be used in a commercial
|
|
* product or activity.
|
|
*
|
|
* - Redistributions that are modified from the original source must include the
|
|
* complete source code, including the source code for all components used by a
|
|
* binary built from the modified sources. However, as a special exception, the
|
|
* source code distributed need not include anything that is normally distributed
|
|
* (in either source or binary form) with the major components (compiler, kernel,
|
|
* and so on) of the operating system on which the executable runs, unless that
|
|
* component itself accompanies the executable.
|
|
*
|
|
* - Redistributions must reproduce the above copyright notice, this list of
|
|
* conditions and the following disclaimer in the documentation and/or other
|
|
* materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************************/
|
|
#ifndef _HW_SCD_
|
|
#define _HW_SCD_
|
|
|
|
#include "cdd.h"
|
|
#include "cdc.h"
|
|
#include "gfx.h"
|
|
#include "pcm.h"
|
|
#include "cd_cart.h"
|
|
|
|
#define scd ext.cd_hw
|
|
|
|
/* 5000000 clocks/s = approx. 3184 clocks/line with a master clock of 53.693175 Mhz */
|
|
/* TODO: use emulated master clock as reference ? */
|
|
#define SCD_CLOCK 50000000
|
|
#define SCYCLES_PER_LINE 3184
|
|
|
|
|
|
/* CD hardware */
|
|
typedef struct
|
|
{
|
|
uint8 bootrom[0x20000]; /* 128K internal BOOTROM */
|
|
uint8 prg_ram[0x80000]; /* 512K PRG-RAM */
|
|
uint8 word_ram[2][0x20000]; /* 2 x 128K Word RAM (1M mode) */
|
|
uint8 word_ram_2M[0x40000]; /* 256K Word RAM (2M mode) */
|
|
uint8 bram[0x2000]; /* 8K Backup RAM */
|
|
reg16_t regs[0x100]; /* 256 x 16-bit ASIC registers */
|
|
uint32 cycles; /* Master clock counter */
|
|
int32 timer; /* Timer counter */
|
|
uint8 pending; /* Pending interrupts */
|
|
uint8 dmna; /* Pending DMNA write status */
|
|
gfx_t gfx_hw; /* Graphics processor */
|
|
cdc_t cdc_hw; /* CD data controller */
|
|
cdd_t cdd_hw; /* CD drive processor */
|
|
pcm_t pcm_hw; /* PCM chip */
|
|
cd_cart_t cartridge; /* Cartridge hardware */
|
|
} cd_hw_t;
|
|
|
|
/* Function prototypes */
|
|
extern void scd_init(void);
|
|
extern void scd_shutdown(void);
|
|
extern void scd_reset(int hard);
|
|
extern void scd_update(unsigned int cycles);
|
|
extern int scd_context_load(uint8 *state);
|
|
extern int scd_context_save(uint8 *state);
|
|
extern int scd_68k_irq_ack(int level);
|
|
extern void prg_ram_dma_w(unsigned int words);
|
|
|
|
#endif
|