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Diffstat (limited to 'src/devices/bus/coco/dragon_serial.cpp')
-rw-r--r-- | src/devices/bus/coco/dragon_serial.cpp | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/devices/bus/coco/dragon_serial.cpp b/src/devices/bus/coco/dragon_serial.cpp new file mode 100644 index 00000000000..c2ecab858d8 --- /dev/null +++ b/src/devices/bus/coco/dragon_serial.cpp @@ -0,0 +1,138 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/*************************************************************************** + + Peaksoft Prestel Module + + Also known as the New Era Interface from Peaksoft/Harry Whitehouse, which + includes a through port for DOS cartridges. + + TODO: + - add throughport, not known how CTS/SCS lines are switched between slots. + +***************************************************************************/ + +#include "emu.h" +#include "dragon_serial.h" +#include "machine/6850acia.h" +#include "machine/clock.h" +#include "bus/rs232/rs232.h" + + +namespace { + +class dragon_serial_device : public device_t, public device_cococart_interface +{ +public: + dragon_serial_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, DRAGON_SERIAL, tag, owner, clock) + , device_cococart_interface(mconfig, *this ) + , m_eprom(*this, "eprom") + , m_acia(*this, "acia") + { + } + +protected: + // device_t overrides + virtual void device_start() override { } + virtual u8 *get_cart_base() override { return m_eprom->base(); } + virtual memory_region *get_cart_memregion() override { return m_eprom; } + + // optional information overrides + virtual void device_add_mconfig(machine_config &config) override ATTR_COLD; + virtual const tiny_rom_entry *device_rom_region() const override ATTR_COLD; + + virtual u8 cts_read(offs_t offset) override; + virtual u8 scs_read(offs_t offset) override; + virtual void scs_write(offs_t offset, u8 data) override; + +private: + required_memory_region m_eprom; + required_device<acia6850_device> m_acia; +}; + + +//------------------------------------------------- +// ROM( dragon_serial ) +//------------------------------------------------- + +ROM_START(dragon_serial) + ROM_REGION(0x2000, "eprom", 0) + ROM_LOAD("comron_peaksoft.rom", 0x0000, 0x2000, CRC(9d18cf46) SHA1(14124dfb4bd78d1907e80d779cd7f3bae30564c9)) +ROM_END + +const tiny_rom_entry *dragon_serial_device::device_rom_region() const +{ + return ROM_NAME( dragon_serial ); +} + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void dragon_serial_device::device_add_mconfig(machine_config &config) +{ + ACIA6850(config, m_acia, 0); + m_acia->txd_handler().set("rs232", FUNC(rs232_port_device::write_txd)); + m_acia->rts_handler().set("rs232", FUNC(rs232_port_device::write_rts)); + m_acia->irq_handler().set([this](int state) { set_line_value(line::NMI, state); }); + + clock_device &rx_clock(CLOCK(config, "rx_clock", 2.4576_MHz_XTAL / 32)); // 1200 baud + rx_clock.signal_handler().set(m_acia, FUNC(acia6850_device::write_rxc)); + + clock_device &tx_clock(CLOCK(config, "tx_clock", 2.4576_MHz_XTAL / 512)); // 75 baud + tx_clock.signal_handler().set(m_acia, FUNC(acia6850_device::write_txc)); + + rs232_port_device &rs232(RS232_PORT(config, "rs232", default_rs232_devices, "null_modem")); + rs232.rxd_handler().set(m_acia, FUNC(acia6850_device::write_rxd)); + rs232.cts_handler().set(m_acia, FUNC(acia6850_device::write_cts)); + rs232.dcd_handler().set(m_acia, FUNC(acia6850_device::write_dcd)).invert(); +} + + +//------------------------------------------------- +// cts_read +//------------------------------------------------- + +u8 dragon_serial_device::cts_read(offs_t offset) +{ + return m_eprom->base()[offset & 0x1fff]; +} + +//------------------------------------------------- +// scs_read +//------------------------------------------------- + +u8 dragon_serial_device::scs_read(offs_t offset) +{ + uint8_t result = 0x00; + + switch (offset) + { + case 0x14: case 0x15: + result = m_acia->read(offset & 1); + break; + } + + return result; +} + +//------------------------------------------------- +// scs_write +//------------------------------------------------- + +void dragon_serial_device::scs_write(offs_t offset, u8 data) +{ + switch (offset) + { + case 0x14: case 0x15: + m_acia->write(offset & 1, data); + break; + } +} + +} // anonymous namespace + + +DEFINE_DEVICE_TYPE_PRIVATE(DRAGON_SERIAL, device_cococart_interface, dragon_serial_device, "dragon_serial", "Dragon Peaksoft Prestel Module") |