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// license:BSD-3-Clause
// copyright-holders:Olivier Galibert
/***************************************************************************
The Konami_1 CPU is a 6809 with opcodes scrambled.
***************************************************************************/
#include "emu.h"
#include "konami1.h"
DEFINE_DEVICE_TYPE(KONAMI1, konami1_device, "konami1", "KONAMI-1")
konami1_device::konami1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: m6809_base_device(mconfig, tag, owner, clock, KONAMI1, 1)
{
m_boundary = 0x0000;
}
void konami1_device::device_start()
{
m_mintf = std::make_unique<mi_konami1>(m_boundary);
m6809_base_device::device_start();
}
u32 konami1_device::disassembler::interface_flags() const
{
return SPLIT_DECRYPTION;
}
u8 konami1_device::disassembler::decrypt8(u8 value, offs_t pc, bool opcode) const
{
if (!opcode || pc < m_boundary)
return value;
switch (pc & 0xa) {
default:
case 0x0: return value ^ 0x22;
case 0x2: return value ^ 0x82;
case 0x8: return value ^ 0x28;
case 0xa: return value ^ 0x88;
}
return value;
}
std::unique_ptr<util::disasm_interface> konami1_device::create_disassembler()
{
return std::make_unique<disassembler>(m_boundary);
}
void konami1_device::set_encryption_boundary(uint16_t adr)
{
m_boundary = adr;
if(m_mintf)
downcast<mi_konami1 *>(m_mintf.get())->m_boundary = adr;
}
konami1_device::mi_konami1::mi_konami1(uint16_t adr)
{
m_boundary = adr;
}
uint8_t konami1_device::mi_konami1::read_opcode(uint16_t adr)
{
uint8_t val = m_scache->read_byte(adr);
if(adr < m_boundary)
return val;
switch(adr & 0xa) {
default:
case 0x0: return val ^ 0x22;
case 0x2: return val ^ 0x82;
case 0x8: return val ^ 0x28;
case 0xa: return val ^ 0x88;
}
}
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