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-rw-r--r--src/devices/machine/ds75160a.cpp111
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diff --git a/src/devices/machine/ds75160a.cpp b/src/devices/machine/ds75160a.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Curt Coder
+/**********************************************************************
+
+ National Semiconductor DS75160A IEEE-488 GPIB Transceiver emulation
+
+**********************************************************************/
+
+#include "ds75160a.h"
+
+
+
+//**************************************************************************
+// DEVICE TYPE DEFINITIONS
+//**************************************************************************
+
+const device_type DS75160A = &device_creator<ds75160a_device>;
+
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// ds75160a_device - constructor
+//-------------------------------------------------
+
+ds75160a_device::ds75160a_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : device_t(mconfig, DS75160A, "DS75160A", tag, owner, clock, "ds75160a", __FILE__),
+ m_read(*this),
+ m_write(*this),
+ m_data(0xff),
+ m_te(0),
+ m_pe(0)
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void ds75160a_device::device_start()
+{
+ // resolve callbacks
+ m_read.resolve_safe(0);
+ m_write.resolve_safe();
+
+ // register for state saving
+ save_item(NAME(m_data));
+ save_item(NAME(m_te));
+ save_item(NAME(m_pe));
+}
+
+
+//-------------------------------------------------
+// read - read data bus
+//-------------------------------------------------
+
+READ8_MEMBER( ds75160a_device::read )
+{
+ UINT8 data = 0;
+
+ if (!m_te)
+ {
+ data = m_read(0);
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// write - write data bus
+//-------------------------------------------------
+
+WRITE8_MEMBER( ds75160a_device::write )
+{
+ m_data = data;
+
+ if (m_te)
+ {
+ m_write((offs_t)0, m_data);
+ }
+}
+
+
+//-------------------------------------------------
+// te_w - transmit enable
+//-------------------------------------------------
+
+WRITE_LINE_MEMBER( ds75160a_device::te_w )
+{
+ if (m_te != state)
+ {
+ m_write((offs_t)0, m_te ? m_data : 0xff);
+ }
+
+ m_te = state;
+}
+
+
+//-------------------------------------------------
+// pe_w - parallel enable
+//-------------------------------------------------
+
+WRITE_LINE_MEMBER( ds75160a_device::pe_w )
+{
+ m_pe = state;
+}