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-rw-r--r--src/devices/bus/vcs_ctrl/trakball.cpp150
1 files changed, 150 insertions, 0 deletions
diff --git a/src/devices/bus/vcs_ctrl/trakball.cpp b/src/devices/bus/vcs_ctrl/trakball.cpp
new file mode 100644
index 00000000000..0da97221762
--- /dev/null
+++ b/src/devices/bus/vcs_ctrl/trakball.cpp
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+// license:BSD-3-Clause
+/**********************************************************************
+
+ Atari CX22/CX80 Trak-Ball
+
+Note: this module only works in trackball mode and not in joystick emulation mode
+
+Reference: Atari, CX22 Trakball Field Service Manual, Rev. 01 (FD100660), November 1983
+
+**********************************************************************/
+
+#include "emu.h"
+#include "trakball.h"
+
+/***************************************************************************
+ CONSTANTS
+***************************************************************************/
+
+#define TRAKBALL_BUTTON_TAG "trackball_buttons"
+#define TRAKBALL_XAXIS_TAG "trackball_x"
+#define TRAKBALL_YAXIS_TAG "trackball_y"
+
+#define TRAKBALL_POS_UNINIT 0xffffffff /* default out-of-range position */
+
+//**************************************************************************
+// DEVICE TYPE DEFINITION
+//**************************************************************************
+
+DEFINE_DEVICE_TYPE(ATARI_TRAKBALL, atari_trakball_device, "atari_trakball", "Atari CX22/CX80 Trak-Ball")
+
+
+//**************************************************************************
+// INPUT PORTS
+//**************************************************************************
+
+static INPUT_PORTS_START(atari_trakball)
+ PORT_START(TRAKBALL_BUTTON_TAG) /* Trak-ball - button */
+ PORT_BIT( 0x0f, IP_ACTIVE_HIGH, IPT_UNUSED )
+ PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_WRITE_LINE_MEMBER(FUNC(atari_trakball_device::trigger_w))
+ PORT_BIT( 0xd0, IP_ACTIVE_LOW, IPT_UNUSED )
+
+ PORT_START(TRAKBALL_XAXIS_TAG) /* Trak-ball - X AXIS */
+ PORT_BIT( 0xff, 0x00, IPT_TRACKBALL_X) PORT_SENSITIVITY(80) PORT_KEYDELTA(0) PORT_PLAYER(1) PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(atari_trakball_device::trakball_moved), 0)
+
+ PORT_START(TRAKBALL_YAXIS_TAG) /* Trak-ball - Y AXIS */
+ PORT_BIT( 0xff, 0x00, IPT_TRACKBALL_Y) PORT_SENSITIVITY(80) PORT_KEYDELTA(0) PORT_PLAYER(1) PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(atari_trakball_device::trakball_moved), 1)
+INPUT_PORTS_END
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// atari_trakball_device - constructor
+//-------------------------------------------------
+
+atari_trakball_device::atari_trakball_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
+ : device_t(mconfig, ATARI_TRAKBALL, tag, owner, clock)
+ , device_vcs_control_port_interface(mconfig, *this)
+ , m_trakballb(*this, TRAKBALL_BUTTON_TAG)
+ , m_trakballxy(*this, { TRAKBALL_XAXIS_TAG, TRAKBALL_YAXIS_TAG })
+ , m_last_pos{ TRAKBALL_POS_UNINIT, TRAKBALL_POS_UNINIT }
+ , m_last_direction{ 0, 0 }
+{
+}
+
+//-------------------------------------------------
+// device_input_ports - device-specific input ports
+//-------------------------------------------------
+
+ioport_constructor atari_trakball_device::device_input_ports() const
+{
+ return INPUT_PORTS_NAME(atari_trakball);
+}
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void atari_trakball_device::device_start()
+{
+ save_item(NAME(m_last_pos));
+ save_item(NAME(m_last_direction));
+}
+
+#define QUADRATURE_ANGLE_RESOLUTION 0x02
+
+//-----------------------------------------------------------------
+// trakbal_pos_and_dir_upd - update tracked position and direction
+//-----------------------------------------------------------------
+
+void atari_trakball_device::trakball_pos_and_dir_upd(int axis)
+{
+ int diff_pos = 0;
+ int cur_pos = 0;
+
+ cur_pos = m_trakballxy[axis]->read();
+ if (m_last_pos[axis] == TRAKBALL_POS_UNINIT) {
+ if (!machine().side_effects_disabled()) {
+ m_last_pos[axis] = cur_pos;
+ }
+ }
+ diff_pos = cur_pos - m_last_pos[axis];
+ // wrap-around the position
+ if (diff_pos > 0x7f) {
+ diff_pos -= 0x100;
+ } else if (diff_pos < -0x80) {
+ diff_pos += 0x100;
+ }
+ if (!machine().side_effects_disabled()) {
+ m_last_pos[axis] = cur_pos;
+ if (diff_pos) {
+ m_last_direction[axis] = diff_pos > 0;
+ }
+ }
+}
+
+//---------------------------------------------------------
+// trakball_moved - called when moved outside of polling
+//---------------------------------------------------------
+
+INPUT_CHANGED_MEMBER( atari_trakball_device::trakball_moved )
+{
+ const int axis(param);
+
+ trakball_pos_and_dir_upd(axis);
+}
+
+//-------------------------------------------------
+// vcs_joy_r - read digital inputs
+//-------------------------------------------------
+
+u8 atari_trakball_device::vcs_joy_r()
+{
+ u8 vcs_joy_return = 0;
+
+ for (int axis = 0; axis < 2; axis++) {
+ trakball_pos_and_dir_upd(axis);
+ }
+
+ vcs_joy_return =
+ m_trakballb->read() |
+ (m_last_direction[0] ? 0x01 : 0x00) |
+ ((m_last_pos[0] & QUADRATURE_ANGLE_RESOLUTION) ? 0x02 : 0x00) |
+ (m_last_direction[1] ? 0x04 : 0x00) |
+ ((m_last_pos[1] & QUADRATURE_ANGLE_RESOLUTION) ? 0x08 : 0x00);
+
+ return vcs_joy_return;
+}