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Diffstat (limited to 'src/devices/bus/odyssey2/rally.cpp')
-rw-r--r--src/devices/bus/odyssey2/rally.cpp59
1 files changed, 59 insertions, 0 deletions
diff --git a/src/devices/bus/odyssey2/rally.cpp b/src/devices/bus/odyssey2/rally.cpp
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+++ b/src/devices/bus/odyssey2/rally.cpp
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+// license:BSD-3-Clause
+// copyright-holders:hap
+/******************************************************************************
+
+Videopac 55/58/59/60 cartridge emulation
+
+Bankswitched ROM via latch, either 16KB/2*8KB, or 4KB+8KB.
+
+Used in:
+- #55: Neutron Star
+- #58: Air Battle
+- #59: Helicopter Rescue
+- #60: Trans American Rally
+
+******************************************************************************/
+
+#include "emu.h"
+#include "rally.h"
+
+DEFINE_DEVICE_TYPE(O2_ROM_RALLY, o2_rally_device, "o2_rally", "Odyssey 2 Videopac 60")
+
+
+//-------------------------------------------------
+// o2_rally_device - constructor
+//-------------------------------------------------
+
+o2_rally_device::o2_rally_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+ o2_rom_device(mconfig, O2_ROM_RALLY, tag, owner, clock)
+{ }
+
+void o2_rally_device::device_start()
+{
+ save_item(NAME(m_control));
+ save_item(NAME(m_bank));
+}
+
+void o2_rally_device::cart_init()
+{
+ if (m_rom_size & (m_rom_size - 1) || m_rom_size < 0x800)
+ fatalerror("o2_rally_device: ROM size must be 2^x\n");
+}
+
+
+//-------------------------------------------------
+// mapper specific handlers
+//-------------------------------------------------
+
+u8 o2_rally_device::read_rom04(offs_t offset)
+{
+ // P10 enables latch output
+ u8 bank = (m_control & 1) ? ~0 : m_bank;
+ return m_rom[(offset + bank * 0x800) & (m_rom_size - 1)];
+}
+
+void o2_rally_device::io_write(offs_t offset, u8 data)
+{
+ if (offset & 0x80 && ~m_control & 0x10)
+ m_bank = data;
+}