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-rw-r--r--src/devices/bus/c64/georam.cpp99
1 files changed, 99 insertions, 0 deletions
diff --git a/src/devices/bus/c64/georam.cpp b/src/devices/bus/c64/georam.cpp
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index 00000000000..d3c30bf029e
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+++ b/src/devices/bus/c64/georam.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Curt Coder
+/**********************************************************************
+
+ Berkeley Softworks GeoRAM emulation
+
+**********************************************************************/
+
+#include "georam.h"
+
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+const device_type C64_GEORAM = &device_creator<c64_georam_cartridge_device>;
+
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// c64_georam_cartridge_device - constructor
+//-------------------------------------------------
+
+c64_georam_cartridge_device::c64_georam_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ device_t(mconfig, C64_GEORAM, "C64 GeoRAM cartridge", tag, owner, clock, "c64_georam", __FILE__),
+ device_c64_expansion_card_interface(mconfig, *this),
+ m_ram(*this, "ram")
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void c64_georam_cartridge_device::device_start()
+{
+ // allocate memory
+ m_ram.allocate(0x80000);
+
+ // state saving
+ save_item(NAME(m_bank));
+}
+
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void c64_georam_cartridge_device::device_reset()
+{
+ m_bank = 0;
+}
+
+
+//-------------------------------------------------
+// c64_cd_r - cartridge data read
+//-------------------------------------------------
+
+UINT8 c64_georam_cartridge_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ if (!io1)
+ {
+ offs_t addr = (m_bank << 8) | (offset & 0xff);
+ data = m_ram[addr];
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// c64_cd_w - cartridge data write
+//-------------------------------------------------
+
+void c64_georam_cartridge_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ if (!io1)
+ {
+ offs_t addr = (m_bank << 8) | (offset & 0xff);
+ m_ram[addr] = data;
+ }
+ else if (!io2)
+ {
+ if (BIT(offset, 0))
+ {
+ m_bank = ((data & 0x1f) << 6) | (m_bank & 0x3f);
+ }
+ else
+ {
+ m_bank = (m_bank & 0x7c0) | (data & 0x3f);
+ }
+ }
+}