diff options
Diffstat (limited to 'src/devices/bus/c64/z80videopak.cpp')
-rw-r--r-- | src/devices/bus/c64/z80videopak.cpp | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/devices/bus/c64/z80videopak.cpp b/src/devices/bus/c64/z80videopak.cpp new file mode 100644 index 00000000000..fc6c3544b2c --- /dev/null +++ b/src/devices/bus/c64/z80videopak.cpp @@ -0,0 +1,213 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder, smf +/* + +Z80 Video Pak +(c) 1983 Data 20 Corporation + +*/ + +#include "emu.h" +#include "z80videopak.h" +#include "screen.h" + + + +//************************************************************************** +// MACROS/CONSTANTS +//************************************************************************** + +#define RAM_SIZE 0x800 + +#define HD46505SP_TAG "mc6845" +#define MC6845_SCREEN_TAG "screen80" + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(C64_Z80VIDEOPAK, c64_z80videopak_device, "c64_z80videopak", "Data20 Z80 Video Pak") + + +//------------------------------------------------- +// ROM( c64_z80videopak ) +//------------------------------------------------- + +ROM_START( c64_z80videopak ) + ROM_REGION( 0x800, HD46505SP_TAG, 0 ) + ROM_LOAD( "c68297 vid pak cg.u18", 0x000, 0x800, CRC(9edf5e58) SHA1(4b244e6d94a7653a2e52c351589f0b469119fb04) ) +ROM_END + + +//------------------------------------------------- +// rom_region - device-specific ROM region +//------------------------------------------------- + +const tiny_rom_entry *c64_z80videopak_device::device_rom_region() const +{ + return ROM_NAME( c64_z80videopak ); +} + +//------------------------------------------------- +// mc6845 +//------------------------------------------------- + +MC6845_UPDATE_ROW( c64_z80videopak_device::crtc_update_row ) +{ + pen_t const *const pen = m_palette->pens(); + + for (int column = 0; column < x_count; column++) + { + uint8_t const code = m_ram[((ma + column) & 0x7ff)]; + uint16_t const addr = (m_case << 10) | ((code & 0x7f) << 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 const x = (column * 8) + bit; + int const color = BIT(data ^ code, 7) && de; + + bitmap.pix(vbp + y, hbp + x) = pen[color]; + + data <<= 1; + } + } +} + +//------------------------------------------------- +// GFXDECODE( c64_videopak ) +//------------------------------------------------- + +static GFXDECODE_START( gfx_c64_z80videopak ) + GFXDECODE_ENTRY(HD46505SP_TAG, 0x0000, gfx_8x8x1, 0, 1) +GFXDECODE_END + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void c64_z80videopak_device::device_add_mconfig(machine_config &config) +{ + c64_cpm_cartridge_device::device_add_mconfig(config); + + screen_device &screen(SCREEN(config, MC6845_SCREEN_TAG, SCREEN_TYPE_RASTER, rgb_t::white())); + screen.set_screen_update(HD46505SP_TAG, FUNC(hd6845s_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_c64_z80videopak); + PALETTE(config, m_palette, palette_device::MONOCHROME); + + HD6845S(config, m_crtc, XTAL(14'318'181) / 8); + 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(c64_z80videopak_device::crtc_update_row)); +} + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// c64_z80videopak_device - constructor +//------------------------------------------------- + +c64_z80videopak_device::c64_z80videopak_device(const machine_config& mconfig, const char* tag, device_t* owner, uint32_t clock) : + c64_cpm_cartridge_device(mconfig, C64_Z80VIDEOPAK, tag, owner, clock), + m_crtc(*this, HD46505SP_TAG), + m_palette(*this, "palette"), + m_char_rom(*this, HD46505SP_TAG), + m_ram(*this, "ram", RAM_SIZE, ENDIANNESS_LITTLE) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void c64_z80videopak_device::device_start() +{ + // state saving + save_item(NAME(m_case)); + + c64_cpm_cartridge_device::device_start(); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void c64_z80videopak_device::device_reset() +{ + m_case = 0; + m_exrom = 0; + + c64_cpm_cartridge_device::device_reset(); +} + + +//------------------------------------------------- +// c64_cd_r - cartridge data read +//------------------------------------------------- + +uint8_t c64_z80videopak_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + if (!roml) + { + if (BIT(offset, 11)) + data = m_ram[offset & 0x7ff]; + else + data = m_roml[offset & 0x7ff]; + } + else if (!io2 && !BIT(offset, 1)) + { + if (BIT(offset, 0)) + data = m_crtc->register_r(); + } + + return data; +} + + +//------------------------------------------------- +// c64_cd_w - cartridge data write +//------------------------------------------------- + +void c64_z80videopak_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + c64_cpm_cartridge_device::c64_cd_w(offset, data, sphi2, ba, roml, romh, io1, io2); + + if ((!m_exrom && offset >= 0x9800 && offset < 0xa000) || + (m_exrom && offset >= 0xf800 && offset < 0x10000)) + { + m_ram[offset & 0x7ff] = data; + } + else if (!io2 && !BIT(offset, 1)) + { + if (!BIT(offset, 0)) + m_crtc->address_w(data); + else + m_crtc->register_w(data); + } + else if (!io2) + { + m_case = BIT(data, 0); + // BIT(data, 1); // unknown + // BIT(data, 2); // unknown + m_exrom = BIT(data, 4); + } +} |