Sega dreamcast bios v1.01d
![sega dreamcast bios v1.01d sega dreamcast bios v1.01d](https://img.appnee.com/appnee.com/NullDC-1.png)
It needs to be expanded with more detail. Treamcast console BIOS, menu translated to Chinese No support for region flags in flash, hardcoded to Japan ram().The Sega Dreamcast BIOS has several known revisions: Void dc_cons_state::aica_map(address_map &map) rw( FUNC(dc_cons_state::dc_arm_aica_r), FUNC(dc_cons_state::dc_arm_aica_w)) rw( FUNC(dc_cons_state::soundram_r), FUNC(dc_cons_state::soundram_w)) /* shared with SH-4 */ Void dc_cons_state::dc_audio_map(address_map &map) rw( FUNC(dc_cons_state::dc_pdtra_r), FUNC(dc_cons_state::dc_pdtra_w)) Void dc_cons_state::dc_port(address_map &map) noprw() // SH-4 operand cache address array mirror( 0x00800000) // access to texture / framebuffer memory (either 32-bit or 64-bit area depending on SB_LMMODE1 register - cannot be written directly, only through dma / store queue
![sega dreamcast bios v1.01d sega dreamcast bios v1.01d](https://i.ytimg.com/vi/WcKY9Eup8_Y/maxresdefault.jpg)
w(m_powervr2, FUNC(powervr2_device::ta_texture_directpath1_w)). w(m_powervr2, FUNC(powervr2_device::ta_fifo_yuv_w)) w(m_powervr2, FUNC(powervr2_device::ta_fifo_poly_w)) mirror( 0x00800000) // access to texture / framebuffer memory (either 32-bit or 64-bit area depending on SB_LMMODE0 register - cannot be written directly, only through dma / store queue
![sega dreamcast bios v1.01d sega dreamcast bios v1.01d](https://windowsland.com/wp-content/uploads/2021/08/dreamcast-emulator.png)
w(m_powervr2, FUNC(powervr2_device::ta_texture_directpath0_w)). share( "dc_ram ") // extra ram on Naomi (mirror on DC) share( "frameram ") // apparently this actually accesses the same memory as the 64-bit texture memory access, but in a different format, keep it apart for now
Sega dreamcast bios v1.01d 64 Bit#
share( "dc_texture_ram ") // texture memory 64 bit access map(0x02800000, 0x02ffffff) AICA wave mem mirror (loopchk g2 bus DMA test)
Sega dreamcast bios v1.01d iso#
Sega Dreamcast BIOS ISO ( DC ISOS) for Sega Dreamcast ROMSsega-dreamcast - bios dc - sega-dreamcast Play Sega Dreamcast BIOS iso for Sega Dreamcast DC isos on your desktop for free. Sega Dreamcast Flash Rom (Eur-Pal) 26539. rw( FUNC(dc_cons_state::soundram_r), FUNC(dc_cons_state::soundram_w)) rw( "aicartc ", FUNC(aicartc_device:: read), FUNC(aicartc_device:: write)). rw( FUNC(dc_cons_state::dc_aica_reg_r), FUNC(dc_cons_state::dc_aica_reg_w)) rw( FUNC(dc_cons_state::dc_modem_r), FUNC(dc_cons_state::dc_modem_w)) m(m_powervr2, FUNC(powervr2_device::ta_map)) m(m_powervr2, FUNC(powervr2_device::pd_dma_map)) rw( FUNC(dc_cons_state::dc_mess_g1_ctrl_r), FUNC(dc_cons_state::dc_mess_g1_ctrl_w)) rw(m_ata, FUNC(ata_interface_device::cs0_r), FUNC(ata_interface_device::cs0_w)). rw(m_ata, FUNC(ata_interface_device::cs1_r), FUNC(ata_interface_device::cs1_w)). rw( FUNC(dc_cons_state::dc_sysctrl_r), FUNC(dc_cons_state::dc_sysctrl_w)) rw( FUNC(dc_cons_state::dc_flash_r), FUNC(dc_cons_state::dc_flash_w)) Void dc_cons_state::dc_map(address_map &map) Void dc_cons_state::dc_flash_w( offs_t offset, uint8_t data) Return m_dcflash-> read(offset+ 0x20000) Uint8_t dc_cons_state::dc_flash_r( offs_t offset) Uint64_t out = PCTRA read() > 16) & 0xffff U8 *rom = (u8 *) memregion( "maincpu ")-> base() Modchip connected to BIOS ROM chip changes 4 bytes (actually bits) as shown below, which allow to boot any region games. M_maincpu-> sh2drc_add_fastram( 0x0c000000, 0x0cffffff, false, dc_ram) M_maincpu-> sh2drc_set_options(SH2DRC_STRICT_VERIFY | SH2DRC_STRICT_PCREL) On a non-jp console is different than these ones, the system shows a black swirl (and nothing boots). 0x1a002 of flash ROM returns the region type (0x30=Japan, 0x31=USA, 0x32=Europe). Tetris 4D: hangs at BPS FMV (bp 0C0B0C4E) Idol Janshi wo Tsukucchaou: pixel aspect is way wrong (stretched and offsetted horizontally) Gundam - Side Story 0079: currently hangs at Bandai logo (regression) F355 Challenge: black screen after Sega logo Carrier: Jaleco logo uses YUV, but y size is halved? Candy Stripe: fills the log with "ATAPI_FEATURES_FLAG_OVL not supported", black screen Old TODO (to be rechecked and moved in XML notes): G1 i/f for GD-ROM needs to be converted in device class and hunted for unsupported features naomi.cpp header for general DC notes įor a comprehensive list of issues to be verified
Sega dreamcast bios v1.01d plus#
RTC error always pops up at start-up, no flash plus bug with ticks (needs rewrite) BelmontĪRM7DI 2.8223 MHz (no T or M extensions)