// 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" #include "screen.h" //************************************************************************** // MACROS/CONSTANTS //************************************************************************** #define VIDEORAM_SIZE 0x800 #define RAM_SIZE 0x10000 #define MC6845_TAG "mc6845" #define MC6845_SCREEN_TAG "screen80" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(VIC20_VIDEO_PAK, vic20_video_pak_device, "vic20_videopak", "Data 20 Video Pak") //------------------------------------------------- // 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_device::device_rom_region() const { return ROM_NAME( videopak ); } //------------------------------------------------- // mc6845 //------------------------------------------------- MC6845_UPDATE_ROW( vic20_video_pak_device::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.pix(vbp + y, hbp + x) = pen[color]; data <<= 1; } } } //------------------------------------------------- // GFXDECODE( vic20_video_pak ) //------------------------------------------------- static GFXDECODE_START( gfx_vic20_video_pak ) GFXDECODE_ENTRY(MC6845_TAG, 0x0000, gfx_8x8x1, 0, 1) GFXDECODE_END //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void vic20_video_pak_device::device_add_mconfig(machine_config &config) { screen_device &screen(SCREEN(config, MC6845_SCREEN_TAG, SCREEN_TYPE_RASTER, rgb_t::white())); screen.set_screen_update(MC6845_TAG, FUNC(mc6845_device::screen_update)); screen.set_size(80*8, 24*8); screen.set_visarea(0, 80*8-1, 0, 24*8-1); screen.set_refresh_hz(50); GFXDECODE(config, "gfxdecode", m_palette, gfx_vic20_video_pak); PALETTE(config, m_palette, palette_device::MONOCHROME); MC6845(config, m_crtc, XTAL(14'318'181) / 8); // HD46505RP or similar m_crtc->set_screen(MC6845_SCREEN_TAG); m_crtc->set_show_border_area(true); m_crtc->set_char_width(8); m_crtc->set_update_row_callback(FUNC(vic20_video_pak_device::crtc_update_row)); } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // vic20_video_pak_device - constructor //------------------------------------------------- vic20_video_pak_device::vic20_video_pak_device(const machine_config &mconfig, const char *tag, device_t *owner, const XTAL &clock) : device_t(mconfig, VIC20_VIDEO_PAK, tag, owner, clock), 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", VIDEORAM_SIZE, ENDIANNESS_LITTLE), m_ram(*this, "ram", RAM_SIZE, ENDIANNESS_LITTLE) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void vic20_video_pak_device::device_start() { } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void vic20_video_pak_device::device_reset() { } //------------------------------------------------- // vic20_cd_r - cartridge data read //------------------------------------------------- uint8_t vic20_video_pak_device::vic20_cd_r(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: if (m_blk5) data = m_blk5[offset & 0x7ff]; break; case 3: data = m_videoram[offset & 0x7ff]; break; } } if (!io2) { if (offset == 0x1bf9) { data = m_crtc->register_r(); } } return data; } //------------------------------------------------- // vic20_cd_w - cartridge data write //------------------------------------------------- void vic20_video_pak_device::vic20_cd_w(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(data); break; case 0x1bf9: m_crtc->register_w(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; } } }