summaryrefslogtreecommitdiffstatshomepage
path: root/src/devices/bus/astrocde/rom.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/devices/bus/astrocde/rom.c')
-rw-r--r--src/devices/bus/astrocde/rom.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/src/devices/bus/astrocde/rom.c b/src/devices/bus/astrocde/rom.c
new file mode 100644
index 00000000000..d8067daa062
--- /dev/null
+++ b/src/devices/bus/astrocde/rom.c
@@ -0,0 +1,99 @@
+// license:BSD-3-Clause
+// copyright-holders:Fabio Priuli
+/***********************************************************************************************************
+
+
+ Bally Astrocade cart emulation
+
+
+ ***********************************************************************************************************/
+
+
+#include "emu.h"
+#include "rom.h"
+
+
+//-------------------------------------------------
+// astrocade_rom_device - constructor
+//-------------------------------------------------
+
+const device_type ASTROCADE_ROM_STD = &device_creator<astrocade_rom_device>;
+const device_type ASTROCADE_ROM_256K = &device_creator<astrocade_rom_256k_device>;
+const device_type ASTROCADE_ROM_512K = &device_creator<astrocade_rom_512k_device>;
+
+
+astrocade_rom_device::astrocade_rom_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
+ : device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+ device_astrocade_cart_interface(mconfig, *this)
+{
+}
+
+astrocade_rom_device::astrocade_rom_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : device_t(mconfig, ASTROCADE_ROM_STD, "Bally Astrocade Standard Carts", tag, owner, clock, "astrocade_rom", __FILE__),
+ device_astrocade_cart_interface(mconfig, *this)
+{
+}
+
+astrocade_rom_256k_device::astrocade_rom_256k_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : astrocade_rom_device(mconfig, ASTROCADE_ROM_256K, "Bally Astrocade 256K Carts", tag, owner, clock, "astrocade_256k", __FILE__)
+{
+}
+
+astrocade_rom_512k_device::astrocade_rom_512k_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : astrocade_rom_device(mconfig, ASTROCADE_ROM_512K, "Bally Astrocade 512K Carts", tag, owner, clock, "astrocade_512k", __FILE__)
+{
+}
+
+
+void astrocade_rom_256k_device::device_start()
+{
+ save_item(NAME(m_base_bank));
+}
+
+void astrocade_rom_256k_device::device_reset()
+{
+ m_base_bank = 0;
+}
+
+void astrocade_rom_512k_device::device_start()
+{
+ save_item(NAME(m_base_bank));
+}
+
+void astrocade_rom_512k_device::device_reset()
+{
+ m_base_bank = 0;
+}
+
+
+/*-------------------------------------------------
+ mapper specific handlers
+ -------------------------------------------------*/
+
+READ8_MEMBER(astrocade_rom_device::read_rom)
+{
+ if (offset < m_rom_size)
+ return m_rom[offset];
+ else
+ return 0xff;
+}
+
+READ8_MEMBER(astrocade_rom_256k_device::read_rom)
+{
+ if (offset < 0x1000) // 0x2000-0x2fff
+ return m_rom[offset + 0x1000 * 0x3f];
+ else if (offset < 0x1fc0) // 0x3000-0x3fbf
+ return m_rom[(offset & 0xfff) + (0x1000 * m_base_bank)];
+ else // 0x3fc0-0x3fff
+ return m_base_bank = offset & 0x3f;
+}
+
+READ8_MEMBER(astrocade_rom_512k_device::read_rom)
+{
+ if (offset < 0x1000) // 0x2000-0x2fff
+ return m_rom[offset + 0x1000 * 0x7f];
+ else if (offset < 0x1f80) // 0x3000-0x3fbf
+ return m_rom[(offset & 0xfff) + (0x1000 * m_base_bank)];
+ else // 0x3fc0-0x3fff
+ return m_base_bank = offset & 0x7f;
+}