// license:BSD-3-Clause // copyright-holders:Nigel Barnes /********************************************************************** Prism VTX 5000 Modem **********************************************************************/ #include "emu.h" #include "vtx5000.h" #include "machine/clock.h" #include "machine/i8251.h" #include "bus/rs232/rs232.h" namespace { class spectrum_vtx5000_device : public device_t, public device_spectrum_expansion_interface { public: spectrum_vtx5000_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, SPECTRUM_VTX5000, tag, owner, clock) , device_spectrum_expansion_interface(mconfig, *this) , m_exp(*this, "exp") , m_usart(*this, "i8251") , m_rom(*this, "rom") { } protected: virtual void device_start() override ATTR_COLD; virtual void device_reset() override ATTR_COLD; virtual void device_add_mconfig(machine_config &config) override ATTR_COLD; virtual const tiny_rom_entry *device_rom_region() const override ATTR_COLD; virtual uint8_t mreq_r(offs_t offset) override; virtual uint8_t iorq_r(offs_t offset) override; virtual void iorq_w(offs_t offset, uint8_t data) override; virtual bool romcs() override; // passthru virtual void pre_opcode_fetch(offs_t offset) override { m_exp->pre_opcode_fetch(offset); } virtual void post_opcode_fetch(offs_t offset) override { m_exp->post_opcode_fetch(offset); } virtual void pre_data_fetch(offs_t offset) override { m_exp->pre_data_fetch(offset); } virtual void post_data_fetch(offs_t offset) override { m_exp->post_data_fetch(offset); } virtual void mreq_w(offs_t offset, uint8_t data) override { if (m_exp->romcs()) m_exp->mreq_w(offset, data); } private: required_device m_exp; required_device m_usart; required_memory_region m_rom; bool m_romcs; }; ROM_START(vtx5000) ROM_REGION( 0x2000, "rom", 0 ) ROM_SYSTEM_BIOS(0, "v31mnet", "V3.1 Micronet") ROMX_LOAD("vtx5000-3-1.rom", 0x0000, 0x2000, CRC(1431505c) SHA1(42ae2b47c44d8c0d6a6c6a2b39a4a25a6d3a4bda), ROM_BIOS(0)) ROM_SYSTEM_BIOS(1, "v31hlink", "V3.1 Homelink") ROMX_LOAD("homelink.rom", 0x0000, 0x2000, CRC(527d7f32) SHA1(4490186845b198ca9191dd711bd38274cba6f04b), ROM_BIOS(1)) ROM_END const tiny_rom_entry *spectrum_vtx5000_device::device_rom_region() const { return ROM_NAME(vtx5000); } //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void spectrum_vtx5000_device::device_add_mconfig(machine_config &config) { I8251(config, m_usart, 2.4576_MHz_XTAL); m_usart->txd_handler().set("modem", FUNC(rs232_port_device::write_txd)); m_usart->dtr_handler().set("modem", FUNC(rs232_port_device::write_dtr)); m_usart->rts_handler().set([this](int state) { m_romcs = state; }); clock_device &rx_clock(CLOCK(config, "rx_clock", 2.4576_MHz_XTAL / 16 / 2)); // 1200 baud rx_clock.signal_handler().set(m_usart, FUNC(i8251_device::write_rxc)); clock_device &tx_clock(CLOCK(config, "tx_clock", 2.4576_MHz_XTAL / 16 / 32)); // 75 baud tx_clock.signal_handler().set(m_usart, FUNC(i8251_device::write_txc)); rs232_port_device &rs232(RS232_PORT(config, "modem", default_rs232_devices, nullptr)); // TCM3101 (internal modem) rs232.rxd_handler().set(m_usart, FUNC(i8251_device::write_rxd)); rs232.dcd_handler().set(m_usart, FUNC(i8251_device::write_dsr)).invert(); // passthru SPECTRUM_EXPANSION_SLOT(config, m_exp, spectrum_expansion_devices, nullptr); m_exp->irq_handler().set(DEVICE_SELF_OWNER, FUNC(spectrum_expansion_slot_device::irq_w)); m_exp->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(spectrum_expansion_slot_device::nmi_w)); m_exp->fb_r_handler().set(DEVICE_SELF_OWNER, FUNC(spectrum_expansion_slot_device::fb_r)); } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void spectrum_vtx5000_device::device_start() { // CTS grounded m_usart->write_cts(0); save_item(NAME(m_romcs)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void spectrum_vtx5000_device::device_reset() { m_romcs = 1; } //************************************************************************** // IMPLEMENTATION //************************************************************************** bool spectrum_vtx5000_device::romcs() { return m_romcs || m_exp->romcs(); } uint8_t spectrum_vtx5000_device::mreq_r(offs_t offset) { uint8_t data = 0xff; if (m_romcs) data = m_rom->base()[offset & 0x1fff]; if (m_exp->romcs()) data &= m_exp->mreq_r(offset); return data; } uint8_t spectrum_vtx5000_device::iorq_r(offs_t offset) { uint8_t data = m_exp->iorq_r(offset); if ((offset & 0x7f) == 0x7f) data = m_usart->read(BIT(offset, 7)); return data; } void spectrum_vtx5000_device::iorq_w(offs_t offset, uint8_t data) { if ((offset & 0x7f) == 0x7f) m_usart->write(BIT(offset, 7), data); m_exp->iorq_w(offset, data); } } // anonymous namespace DEFINE_DEVICE_TYPE_PRIVATE(SPECTRUM_VTX5000, device_spectrum_expansion_interface, spectrum_vtx5000_device, "spectrum_vtx5000", "Prism VTX 5000 Modem")