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AmigActive 10
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AACD 10.iso
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MAME
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machine
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flstory.c
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C/C++ Source or Header
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2000-04-23
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139 lines
/***************************************************************************
machine.c
Functions to emulate general aspects of the machine (RAM, ROM, interrupts,
I/O ports)
***************************************************************************/
#include "driver.h"
static unsigned char from_main,from_mcu;
static int mcu_sent = 0,main_sent = 0;
/***************************************************************************
Fairy Land Story 68705 protection interface
The following is ENTIRELY GUESSWORK!!!
***************************************************************************/
static unsigned char portA_in,portA_out,ddrA;
READ_HANDLER( flstory_68705_portA_r )
{
//logerror("%04x: 68705 port A read %02x\n",cpu_get_pc(),portA_in);
return (portA_out & ddrA) | (portA_in & ~ddrA);
}
WRITE_HANDLER( flstory_68705_portA_w )
{
//logerror("%04x: 68705 port A write %02x\n",cpu_get_pc(),data);
portA_out = data;
}
WRITE_HANDLER( flstory_68705_ddrA_w )
{
ddrA = data;
}
/*
* Port B connections:
*
* all bits are logical 1 when read (+5V pullup)
*
* 1 W when 1->0, enables latch which brings the command from main CPU (read from port A)
* 2 W when 0->1, copies port A to the latch for the main CPU
*/
static unsigned char portB_in,portB_out,ddrB;
READ_HANDLER( flstory_68705_portB_r )
{
return (portB_out & ddrB) | (portB_in & ~ddrB);
}
WRITE_HANDLER( flstory_68705_portB_w )
{
//logerror("%04x: 68705 port B write %02x\n",cpu_get_pc(),data);
if ((ddrB & 0x02) && (~data & 0x02) && (portB_out & 0x02))
{
portA_in = from_main;
if (main_sent) cpu_set_irq_line(2,0,CLEAR_LINE);
main_sent = 0;
logerror("read command %02x from main cpu\n",portA_in);
}
if ((ddrB & 0x04) && (data & 0x04) && (~portB_out & 0x04))
{
logerror("send command %02x to main cpu\n",portA_out);
from_mcu = portA_out;
mcu_sent = 1;
}
portB_out = data;
}
WRITE_HANDLER( flstory_68705_ddrB_w )
{
ddrB = data;
}
static unsigned char portC_in,portC_out,ddrC;
READ_HANDLER( flstory_68705_portC_r )
{
portC_in = 0;
if (main_sent) portC_in |= 0x01;
if (!mcu_sent) portC_in |= 0x02;
//logerror("%04x: 68705 port C read %02x\n",cpu_get_pc(),portC_in);
return (portC_out & ddrC) | (portC_in & ~ddrC);
}
WRITE_HANDLER( flstory_68705_portC_w )
{
logerror("%04x: 68705 port C write %02x\n",cpu_get_pc(),data);
portC_out = data;
}
WRITE_HANDLER( flstory_68705_ddrC_w )
{
ddrC = data;
}
WRITE_HANDLER( flstory_mcu_w )
{
logerror("%04x: mcu_w %02x\n",cpu_get_pc(),data);
from_main = data;
main_sent = 1;
cpu_set_irq_line(2,0,ASSERT_LINE);
}
READ_HANDLER( flstory_mcu_r )
{
logerror("%04x: mcu_r %02x\n",cpu_get_pc(),from_mcu);
mcu_sent = 0;
return from_mcu;
}
READ_HANDLER( flstory_mcu_status_r )
{
int res = 0;
/* bit 0 = when 1, mcu is ready to receive data from main cpu */
/* bit 1 = when 1, mcu has sent data to the main cpu */
//logerror("%04x: mcu_status_r\n",cpu_get_pc());
if (!main_sent) res |= 0x01;
if (mcu_sent) res |= 0x02;
return res;
}