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// license:BSD-3-Clause
// copyright-holders:Zsolt Vasvari, Couriersud
#include "emu.h"
#include "includes/btime.h"
#define BASE 0xb000
READ8_MEMBER(btime_state::mmonkey_protection_r)
{
uint8_t *RAM = memregion("maincpu")->base();
int ret = 0;
if (offset == 0x0000)
ret = m_protection_status;
else if (offset == 0x0e00)
ret = m_protection_ret;
else if (offset >= 0x0d00 && offset <= 0x0d02)
ret = RAM[BASE + offset]; /* addition result */
else
logerror("Unknown protection read. PC=%04X Offset=%04X\n", m_maincpu->pc(), offset);
return ret;
}
WRITE8_MEMBER(btime_state::mmonkey_protection_w)
{
uint8_t *RAM = memregion("maincpu")->base();
if (offset == 0)
{
/* protection trigger */
if (data == 0)
{
int i, s1, s2, r;
switch (m_protection_command)
{
case 0: /* score addition */
s1 = (1 * (RAM[BASE + 0x0d00] & 0x0f)) + (10 * (RAM[BASE + 0x0d00] >> 4)) +
(100 * (RAM[BASE + 0x0d01] & 0x0f)) + (1000 * (RAM[BASE + 0x0d01] >> 4)) +
(10000 * (RAM[BASE + 0x0d02] & 0x0f)) + (100000 * (RAM[BASE + 0x0d02] >> 4));
s2 = (1 * (RAM[BASE + 0x0d03] & 0x0f)) + (10 * (RAM[BASE + 0x0d03] >> 4)) +
(100 * (RAM[BASE + 0x0d04] & 0x0f)) + (1000 * (RAM[BASE + 0x0d04] >> 4)) +
(10000 * (RAM[BASE + 0x0d05] & 0x0f)) + (100000 * (RAM[BASE + 0x0d05] >> 4));
r = s1 + s2;
RAM[BASE + 0x0d00] = (r % 10); r /= 10;
RAM[BASE + 0x0d00] |= ((r % 10) << 4); r /= 10;
RAM[BASE + 0x0d01] = (r % 10); r /= 10;
RAM[BASE + 0x0d01] |= ((r % 10) << 4); r /= 10;
RAM[BASE + 0x0d02] = (r % 10); r /= 10;
RAM[BASE + 0x0d02] |= ((r % 10) << 4);
break;
case 1: /* decryption */
/* Compute return value by searching the decryption table. */
/* During the search the status should be 2, but we're done */
/* instanteniously in emulation time */
for (i = 0; i < 0x100; i++)
{
if (RAM[BASE + 0x0f00 + i] == m_protection_value)
{
m_protection_ret = i;
break;
}
}
break;
default:
logerror("Unemulated protection command=%02X. PC=%04X\n", m_protection_command, m_maincpu->pc());
break;
}
m_protection_status = 0;
}
}
else if (offset == 0x0c00)
m_protection_command = data;
else if (offset == 0x0e00)
m_protection_value = data;
else if (offset >= 0x0f00)
RAM[BASE + offset] = data; /* decrypt table */
else if (offset >= 0x0d00 && offset <= 0x0d05)
RAM[BASE + offset] = data; /* source table */
else
logerror("Unknown protection write=%02X. PC=%04X Offset=%04X\n", data, m_maincpu->pc(), offset);
}
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