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-rw-r--r--src/devices/bus/tanbus/tanram.cpp93
1 files changed, 93 insertions, 0 deletions
diff --git a/src/devices/bus/tanbus/tanram.cpp b/src/devices/bus/tanbus/tanram.cpp
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+++ b/src/devices/bus/tanbus/tanram.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Nigel Barnes
+/**********************************************************************
+
+ Tangerine TANRAM (MT013 Iss2)
+
+ http://www.microtan.ukpc.net/pageProducts.html#RAM
+
+**********************************************************************/
+
+
+#include "emu.h"
+#include "tanram.h"
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+DEFINE_DEVICE_TYPE(TANBUS_TANRAM, tanbus_tanram_device, "tanbus_tanram", "Tangerine Tanram Board")
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// tanbus_tanram_device - constructor
+//-------------------------------------------------
+
+tanbus_tanram_device::tanbus_tanram_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : device_t(mconfig, TANBUS_TANRAM, tag, owner, clock)
+ , device_tanbus_interface(mconfig, *this)
+{
+}
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void tanbus_tanram_device::device_start()
+{
+ m_ram = std::make_unique<uint8_t[]>(0x9c00);
+
+ save_pointer(NAME(m_ram), 0x9c00);
+}
+
+//-------------------------------------------------
+// read - card read
+//-------------------------------------------------
+
+uint8_t tanbus_tanram_device::read(offs_t offset, int inhrom, int inhram, int be)
+{
+ uint8_t data = 0xff;
+
+ if (be && !inhram)
+ {
+ /* 32K dynamic ram */
+ if ((offset >= 0x2000) && (offset < 0xa000))
+ {
+ data = m_ram[offset - 0x2000];
+ }
+
+ /* 7K static ram */
+ if ((offset >= 0xa000) && (offset < 0xbc00))
+ {
+ data = m_ram[offset - 0xa000];
+ }
+ }
+ return data;
+}
+
+//-------------------------------------------------
+// write - card write
+//-------------------------------------------------
+
+void tanbus_tanram_device::write(offs_t offset, uint8_t data, int inhrom, int inhram, int be)
+{
+ if (be && !inhram)
+ {
+ /* 32K dynamic ram */
+ if ((offset >= 0x2000) && (offset < 0xa000))
+ {
+ m_ram[offset - 0x2000] = data;
+ }
+
+ /* 7K static ram */
+ if ((offset >= 0xa000) && (offset < 0xbc00))
+ {
+ m_ram[offset - 0xa000] = data;
+ }
+ }
+}