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// license:BSD-3-Clause
// copyright-holders:Wilbert Pol
#include "emu.h"
#include "msx_s1985.h"
const device_type MSX_S1985 = &device_creator<msx_s1985_device>;
msx_s1985_device::msx_s1985_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: msx_switched_device(mconfig, MSX_S1985, "MSX-Engine S1985", tag, owner, clock, "msx_s1985", __FILE__)
, m_6_1(0)
, m_6_2(0)
, m_7(0)
{
}
uint8_t msx_s1985_device::get_id()
{
return 0xFE;
}
READ8_MEMBER(msx_s1985_device::io_read)
{
switch (offset)
{
case 0:
return ~get_id();
case 7:
{
uint8_t data = (m_7 & 0x80) ? m_6_2 : m_6_1;
m_7 = ( m_7 << 1 ) | ( m_7 >> 7 );
return data;
}
default:
printf("msx_s1985: unhandled read from offset %02x\n", offset);
break;
}
return 0xFF;
}
WRITE8_MEMBER(msx_s1985_device::io_write)
{
switch (offset)
{
case 6:
m_6_2 = m_6_1;
m_6_1 = data;
break;
case 7:
m_7 = data;
break;
default:
printf("msx_s1985: unhandled write %02x to offset %02x\n", data, offset);
break;
}
}
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