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Diffstat (limited to 'src/devices/cpu/m6502/m6504.cpp')
-rw-r--r--src/devices/cpu/m6502/m6504.cpp61
1 files changed, 61 insertions, 0 deletions
diff --git a/src/devices/cpu/m6502/m6504.cpp b/src/devices/cpu/m6502/m6504.cpp
new file mode 100644
index 00000000000..f2ae2c4b6d9
--- /dev/null
+++ b/src/devices/cpu/m6502/m6504.cpp
@@ -0,0 +1,61 @@
+// license:BSD-3-Clause
+// copyright-holders:Olivier Galibert
+/***************************************************************************
+
+ m6504.c
+
+ Mostek 6502, NMOS variant with reduced address bus
+
+***************************************************************************/
+
+#include "emu.h"
+#include "m6504.h"
+
+const device_type M6504 = &device_creator<m6504_device>;
+
+m6504_device::m6504_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ m6502_device(mconfig, M6504, "M6504", tag, owner, clock, "m6504", __FILE__)
+{
+ program_config.m_addrbus_width = 13;
+ sprogram_config.m_addrbus_width = 13;
+}
+
+void m6504_device::device_start()
+{
+ if(direct_disabled)
+ mintf = new mi_6504_nd;
+ else
+ mintf = new mi_6504_normal;
+
+ init();
+}
+
+UINT8 m6504_device::mi_6504_normal::read(UINT16 adr)
+{
+ return program->read_byte(adr & 0x1fff);
+}
+
+UINT8 m6504_device::mi_6504_normal::read_sync(UINT16 adr)
+{
+ return sdirect->read_byte(adr & 0x1fff);
+}
+
+UINT8 m6504_device::mi_6504_normal::read_arg(UINT16 adr)
+{
+ return direct->read_byte(adr & 0x1fff);
+}
+
+void m6504_device::mi_6504_normal::write(UINT16 adr, UINT8 val)
+{
+ program->write_byte(adr & 0x1fff, val);
+}
+
+UINT8 m6504_device::mi_6504_nd::read_sync(UINT16 adr)
+{
+ return sprogram->read_byte(adr & 0x1fff);
+}
+
+UINT8 m6504_device::mi_6504_nd::read_arg(UINT16 adr)
+{
+ return program->read_byte(adr & 0x1fff);
+}