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-rw-r--r--src/devices/bus/sms_ctrl/multitap.cpp154
1 files changed, 154 insertions, 0 deletions
diff --git a/src/devices/bus/sms_ctrl/multitap.cpp b/src/devices/bus/sms_ctrl/multitap.cpp
new file mode 100644
index 00000000000..fd098b82c18
--- /dev/null
+++ b/src/devices/bus/sms_ctrl/multitap.cpp
@@ -0,0 +1,154 @@
+// license:BSD-3-Clause
+// copyright-holders:Fabio Priuli
+/**********************************************************************
+
+ Furrtek's homemade multitap emulation
+
+**********************************************************************/
+
+#include "multitap.h"
+
+
+// Scheme: http://www.smspower.org/uploads/Homebrew/BOoM-SMS-sms4p_2.png
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+const device_type SMS_MULTITAP = &device_creator<sms_multitap_device>;
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// sms_multitap_device - constructor
+//-------------------------------------------------
+
+sms_multitap_device::sms_multitap_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ device_t(mconfig, SMS_MULTITAP, "Sega SMS Multitap", tag, owner, clock, "sms_multitap", __FILE__),
+ device_sms_control_port_interface(mconfig, *this),
+ m_subctrl1_port(*this, "ctrl1"),
+ m_subctrl2_port(*this, "ctrl2"),
+ m_subctrl3_port(*this, "ctrl3"),
+ m_subctrl4_port(*this, "ctrl4"),
+ m_read_state(0),
+ m_last_data(0)
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void sms_multitap_device::device_start()
+{
+ save_item(NAME(m_read_state));
+ save_item(NAME(m_last_data));
+
+ m_subctrl1_port->device_start();
+ m_subctrl2_port->device_start();
+ m_subctrl3_port->device_start();
+ m_subctrl4_port->device_start();
+}
+
+
+//-------------------------------------------------
+// sms_peripheral_r - multitap read
+//-------------------------------------------------
+
+UINT8 sms_multitap_device::peripheral_r()
+{
+ UINT8 data = 0xff;
+
+ switch(m_read_state)
+ {
+ case 0:
+ data = m_subctrl1_port->port_r();
+ break;
+ case 1:
+ data = m_subctrl2_port->port_r();
+ break;
+ case 2:
+ data = m_subctrl3_port->port_r();
+ break;
+ case 3:
+ data = m_subctrl4_port->port_r();
+ break;
+ }
+
+ // force TH level high (1), as the line is not connected to subports.
+ data |= 0x40;
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// sms_peripheral_w - multitap write
+//-------------------------------------------------
+
+void sms_multitap_device::peripheral_w(UINT8 data)
+{
+ UINT8 output_data;
+
+ // check if TH level is low (0) and was high (1)
+ if (!(data & 0x40) && (m_last_data & 0x40))
+ {
+ m_read_state = (m_read_state + 1) & 3;
+ }
+ m_last_data = data;
+
+ // output default TH level (1), as the line is not connected to subports.
+ output_data = data | 0x40;
+
+ switch(m_read_state)
+ {
+ case 0:
+ m_subctrl1_port->port_w(output_data);
+ break;
+ case 1:
+ m_subctrl2_port->port_w(output_data);
+ break;
+ case 2:
+ m_subctrl3_port->port_w(output_data);
+ break;
+ case 3:
+ m_subctrl4_port->port_w(output_data);
+ break;
+ }
+}
+
+
+//-------------------------------------------------
+// machine_config_additions - device-specific
+// machine configurations
+//-------------------------------------------------
+
+READ32_MEMBER( sms_multitap_device::pixel_r )
+{
+ return m_port->pixel_r();
+}
+
+
+static MACHINE_CONFIG_FRAGMENT( multitap_slot )
+ // Controller subports setup, without the TH callback declaration,
+ // because the circuit scheme shows TH of subports without connection.
+ MCFG_SMS_CONTROL_PORT_ADD("ctrl1", sms_control_port_devices, "joypad")
+ MCFG_SMS_CONTROL_PORT_PIXEL_HANDLER(READ32(sms_multitap_device, pixel_r))
+ MCFG_SMS_CONTROL_PORT_ADD("ctrl2", sms_control_port_devices, "joypad")
+ MCFG_SMS_CONTROL_PORT_PIXEL_HANDLER(READ32(sms_multitap_device, pixel_r))
+ MCFG_SMS_CONTROL_PORT_ADD("ctrl3", sms_control_port_devices, "joypad")
+ MCFG_SMS_CONTROL_PORT_PIXEL_HANDLER(READ32(sms_multitap_device, pixel_r))
+ MCFG_SMS_CONTROL_PORT_ADD("ctrl4", sms_control_port_devices, "joypad")
+ MCFG_SMS_CONTROL_PORT_PIXEL_HANDLER(READ32(sms_multitap_device, pixel_r))
+MACHINE_CONFIG_END
+
+
+machine_config_constructor sms_multitap_device::device_mconfig_additions() const
+{
+ return MACHINE_CONFIG_NAME( multitap_slot );
+}