summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/machine/konami1.cpp
blob: c0240bcbc78634aed968ff84e8336113c6b69f53 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
// license:BSD-3-Clause
// copyright-holders:Olivier Galibert
/***************************************************************************

  The Konami_1 CPU is a 6809 with opcodes scrambled.

***************************************************************************/

#include "emu.h"
#include "konami1.h"

const device_type KONAMI1 = &device_creator<konami1_device>;

konami1_device::konami1_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
	: m6809_base_device(mconfig, "KONAMI-1", tag, owner, clock, KONAMI1, 1, "konami1", __FILE__)
{
	m_boundary = 0x0000;
}

void konami1_device::device_start()
{
	m_mintf = new mi_konami1(m_boundary);
	m6809_base_device::device_start();
}

void konami1_device::set_encryption_boundary(UINT16 adr)
{
	m_boundary = adr;
	if(m_mintf)
		static_cast<mi_konami1 *>(m_mintf)->m_boundary = adr;
}

konami1_device::mi_konami1::mi_konami1(UINT16 adr)
{
	m_boundary = adr;
}

UINT8 konami1_device::mi_konami1::read_opcode(UINT16 adr)
{
	UINT8 val = m_sdirect->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;
	}
}