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Diffstat (limited to 'src/devices/bus/coco/dragon_serial.cpp')
-rw-r--r--src/devices/bus/coco/dragon_serial.cpp138
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
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index 00000000000..c2ecab858d8
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+++ b/src/devices/bus/coco/dragon_serial.cpp
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+// 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")