// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** Data 20 Corporation Video Pak cartridge emulation aka Data 20 Display Manager aka Protecto 40/80 **********************************************************************/ #include "emu.h" #include "videopak.h" //************************************************************************** // MACROS/CONSTANTS //************************************************************************** #define VIDEORAM_SIZE 0x800 #define RAM_SIZE 0x10000 #define MC6845_TAG "mc6845" #define MC6845_SCREEN_TAG "screen80" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** const device_type VIC20_VIDEO_PAK = &device_creator; //------------------------------------------------- // ROM( videopak ) //------------------------------------------------- ROM_START( videopak ) ROM_REGION( 0x800, MC6845_TAG, 0 ) // ROM has been borrowed from the C64 XL80 cartridge ROM_LOAD( "chargen", 0x000, 0x800, BAD_DUMP CRC(9edf5e58) SHA1(4b244e6d94a7653a2e52c351589f0b469119fb04) ) ROM_END //------------------------------------------------- // rom_region - device-specific ROM region //------------------------------------------------- const tiny_rom_entry *vic20_video_pak_t::device_rom_region() const { return ROM_NAME( videopak ); } //------------------------------------------------- // mc6845 //------------------------------------------------- MC6845_UPDATE_ROW( vic20_video_pak_t::crtc_update_row ) { const pen_t *pen = m_palette->pens(); for (int column = 0; column < x_count; column++) { uint8_t code = m_videoram[((ma + column) & 0x7ff)]; uint16_t addr = (code << 3) | (ra & 0x07); uint8_t data = m_char_rom->base()[addr & 0x7ff]; if (column == cursor_x) { data = 0xff; } for (int bit = 0; bit < 8; bit++) { int x = (column * 8) + bit; int color = BIT(data, 7) && de; bitmap.pix32(vbp + y, hbp + x) = pen[color]; data <<= 1; } } } //------------------------------------------------- // GFXDECODE( vic20_video_pak ) //------------------------------------------------- static GFXDECODE_START( vic20_video_pak ) GFXDECODE_ENTRY(MC6845_TAG, 0x0000, gfx_8x8x1, 0, 1) GFXDECODE_END //------------------------------------------------- // MACHINE_CONFIG_FRAGMENT( vic20_video_pak ) //------------------------------------------------- static MACHINE_CONFIG_FRAGMENT( vic20_video_pak ) MCFG_SCREEN_ADD_MONOCHROME(MC6845_SCREEN_TAG, RASTER, rgb_t::white()) MCFG_SCREEN_UPDATE_DEVICE(MC6845_TAG, h46505_device, screen_update) MCFG_SCREEN_SIZE(80*8, 24*8) MCFG_SCREEN_VISIBLE_AREA(0, 80*8-1, 0, 24*8-1) MCFG_SCREEN_REFRESH_RATE(50) MCFG_GFXDECODE_ADD("gfxdecode", "palette", vic20_video_pak) MCFG_PALETTE_ADD_MONOCHROME("palette") MCFG_MC6845_ADD(MC6845_TAG, H46505, MC6845_SCREEN_TAG, XTAL_14_31818MHz / 8) MCFG_MC6845_SHOW_BORDER_AREA(true) MCFG_MC6845_CHAR_WIDTH(8) MCFG_MC6845_UPDATE_ROW_CB(vic20_video_pak_t, crtc_update_row) MACHINE_CONFIG_END //------------------------------------------------- // machine_config_additions - device-specific // machine configurations //------------------------------------------------- machine_config_constructor vic20_video_pak_t::device_mconfig_additions() const { return MACHINE_CONFIG_NAME( vic20_video_pak ); } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // vic20_video_pak_t - constructor //------------------------------------------------- vic20_video_pak_t::vic20_video_pak_t(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, VIC20_VIDEO_PAK, "Data 20 Video Pak", tag, owner, clock, "videopak", __FILE__), device_vic20_expansion_card_interface(mconfig, *this), m_crtc(*this, MC6845_TAG), m_palette(*this, "palette"), m_char_rom(*this, MC6845_TAG), m_videoram(*this, "videoram"), m_ram(*this, "ram") { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void vic20_video_pak_t::device_start() { // allocate memory m_videoram.allocate(VIDEORAM_SIZE); m_ram.allocate(RAM_SIZE); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void vic20_video_pak_t::device_reset() { } //------------------------------------------------- // vic20_cd_r - cartridge data read //------------------------------------------------- uint8_t vic20_video_pak_t::vic20_cd_r(address_space &space, offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) { if (!m_ram_enable) { if (m_bank_size) { if (!blk1) { offs_t addr = m_bank_msb << 15 | m_bank_lsb << 14 | offset; data = m_ram[addr]; } if (!blk2) { offs_t addr = m_bank_msb << 15 | m_bank_lsb << 14 | 0x2000 | offset; data = m_ram[addr]; } } else { if (!blk1) { offs_t addr = m_bank_msb << 15 | offset; data = m_ram[addr]; } if (!blk2) { offs_t addr = m_bank_msb << 15 | 0x2000 | offset; data = m_ram[addr]; } if (!blk3) { offs_t addr = m_bank_msb << 15 | 0x4000 | offset; data = m_ram[addr]; } } } if (!blk5) { switch ((offset >> 11) & 0x03) { case 0: data = m_blk5[offset & 0x7ff]; break; case 3: data = m_videoram[offset & 0x7ff]; break; } } if (!io2) { if (offset == 0x1bf9) { data = m_crtc->register_r(space, 0); } } return data; } //------------------------------------------------- // vic20_cd_w - cartridge data write //------------------------------------------------- void vic20_video_pak_t::vic20_cd_w(address_space &space, offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) { if (!m_ram_enable) { if (m_bank_size) { if (!blk1) { offs_t addr = m_bank_msb << 15 | m_bank_lsb << 14 | offset; m_ram[addr] = data; } if (!blk2) { offs_t addr = m_bank_msb << 15 | m_bank_lsb << 14 | 0x2000 | offset; m_ram[addr] = data; } } else { if (!blk1) { offs_t addr = m_bank_msb << 15 | offset; m_ram[addr] = data; } if (!blk2) { offs_t addr = m_bank_msb << 15 | 0x2000 | offset; m_ram[addr] = data; } if (!blk3) { offs_t addr = m_bank_msb << 15 | 0x4000 | offset; m_ram[addr] = data; } } } if (!blk5) { switch ((offset >> 11) & 0x03) { case 3: m_videoram[offset & 0x7ff] = data; break; } } if (!io2) { switch (offset) { case 0x1bf8: m_crtc->address_w(space, 0, data); break; case 0x1bf9: m_crtc->register_w(space, 0, data); break; case 0x1bfc: /* bit description 0 0 = upper case, 1 = lower case 1 bank size: 0 = 2x24KB, 1 = 4x16KB 2 16KB mode address LSB 3 memory address MSB 4 0 = enable RAM, 1 = disable RAM 5 0 = 40 columns, 1 = 80 columns (Data 20 Video Manager) */ m_case = BIT(data, 0); m_bank_size = BIT(data, 1); m_bank_lsb = BIT(data, 2); m_bank_msb = BIT(data, 3); m_ram_enable = BIT(data, 4); m_columns = BIT(data, 5); break; } } }