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Diffstat (limited to 'src/devices/bus/msx_cart/holy_quran.cpp')
-rw-r--r--src/devices/bus/msx_cart/holy_quran.cpp119
1 files changed, 119 insertions, 0 deletions
diff --git a/src/devices/bus/msx_cart/holy_quran.cpp b/src/devices/bus/msx_cart/holy_quran.cpp
new file mode 100644
index 00000000000..cb9d0b850a7
--- /dev/null
+++ b/src/devices/bus/msx_cart/holy_quran.cpp
@@ -0,0 +1,119 @@
+// license:BSD-3-Clause
+// copyright-holders:Wilbert Pol
+#include "emu.h"
+#include "holy_quran.h"
+
+
+const device_type MSX_CART_HOLY_QURAN = &device_creator<msx_cart_holy_quran>;
+
+
+msx_cart_holy_quran::msx_cart_holy_quran(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : device_t(mconfig, MSX_CART_HOLY_QURAN, "MSX Cartridge - Holy Quran", tag, owner, clock, "msx_cart_holy_quran", __FILE__)
+ , msx_cart_interface(mconfig, *this)
+ , m_decrypt(false)
+{
+ for (int i = 0; i < 4; i++)
+ {
+ m_selected_bank[i] = 0;
+ m_bank_base[i] = NULL;
+ }
+
+ /* protection uses a simple rotation on databus, some lines inverted:
+ D0 D4 D4 D5
+ D1 ~ D3 D5 ~ D2
+ D2 ~ D6 D6 D7
+ D3 ~ D0 D7 D1 */
+ for (int i=0; i < 0x100; i++)
+ {
+ m_lookup_prot[i] = (((i << 4) & 0x50) | ((i >> 3) & 5) | ((i << 1) & 0xa0) | ((i << 2) & 8) | ((i >> 6) & 2)) ^ 0x4d;
+ }
+}
+
+
+void msx_cart_holy_quran::device_start()
+{
+ save_item(NAME(m_selected_bank));
+ save_item(NAME(m_decrypt));
+
+ machine().save().register_postload(save_prepost_delegate(FUNC(msx_cart_holy_quran::restore_banks), this));
+}
+
+
+void msx_cart_holy_quran::restore_banks()
+{
+ m_bank_base[0] = get_rom_base() + (m_selected_bank[0] & 0x7f) * 0x2000;
+ m_bank_base[1] = get_rom_base() + (m_selected_bank[1] & 0x7f) * 0x2000;
+ m_bank_base[2] = get_rom_base() + (m_selected_bank[2] & 0x7f) * 0x2000;
+ m_bank_base[3] = get_rom_base() + (m_selected_bank[3] & 0x7f) * 0x2000;
+}
+
+
+void msx_cart_holy_quran::device_reset()
+{
+ for (int i = 0; i < 4; i++)
+ {
+ m_selected_bank[i] = 0;
+ }
+}
+
+
+void msx_cart_holy_quran::initialize_cartridge()
+{
+ if (get_rom_size() != 0x100000)
+ {
+ fatalerror("holy_quran: Invalid ROM size\n");
+ }
+
+ restore_banks();
+}
+
+
+READ8_MEMBER(msx_cart_holy_quran::read_cart)
+{
+ if (offset >= 0x4000 && offset < 0xc000)
+ {
+ UINT8 data = m_bank_base[(offset - 0x4000) >> 13][offset & 0x1fff];
+
+ if (m_decrypt)
+ {
+ return m_lookup_prot[data];
+ }
+
+ // The decryption should actually start working after the first M1 cycle executing something
+ // from the cartridge.
+ if (offset == ((m_rom[3] << 8) | m_rom[2]) && !space.debugger_access())
+ {
+ m_decrypt = true;
+ }
+
+ return data;
+ }
+ return 0xff;
+}
+
+
+WRITE8_MEMBER(msx_cart_holy_quran::write_cart)
+{
+ switch (offset)
+ {
+ case 0x5000:
+ m_selected_bank[0] = data;
+ restore_banks();
+ break;
+ case 0x5400:
+ m_selected_bank[1] = data;
+ restore_banks();
+ break;
+ case 0x5800:
+ m_selected_bank[2] = data;
+ restore_banks();
+ break;
+ case 0x5c00:
+ m_selected_bank[3] = data;
+ restore_banks();
+ break;
+ default:
+ logerror("msx_cart_holy_quran: unhandled write %02x to %04x\n", data, offset);
+ break;
+ }
+}