// license:GPL-2.0+
// copyright-holders:Lee Hammerton, Dirk Best
/***************************************************************************
Miles Gordon Technology SAM Coupe
***************************************************************************/
#include "emu.h"
#include "includes/samcoupe.h"
/***************************************************************************
CONSTANTS
***************************************************************************/
#define LMPR_RAM0 0x20 /* If bit set ram is paged into bank 0, else its rom0 */
#define LMPR_ROM1 0x40 /* If bit set rom1 is paged into bank 3, else its ram */
#define HMPR_MCNTRL 0x80 /* If set external RAM is enabled */
/***************************************************************************
MEMORY BANKING
***************************************************************************/
READ8_MEMBER(samcoupe_state::sam_bank1_r)
{
if (sam_bank_read_ptr[0])
return sam_bank_read_ptr[0][offset];
return 0xff;
}
WRITE8_MEMBER(samcoupe_state::sam_bank1_w)
{
if (sam_bank_write_ptr[0])
sam_bank_write_ptr[0][offset] = data;
}
READ8_MEMBER(samcoupe_state::sam_bank2_r)
{
if (sam_bank_read_ptr[1])
return sam_bank_read_ptr[1][offset];
return 0xff;
}
WRITE8_MEMBER(samcoupe_state::sam_bank2_w)
{
if (sam_bank_write_ptr[1])
sam_bank_write_ptr[1][offset] = data;
}
READ8_MEMBER(samcoupe_state::sam_bank3_r)
{
if (sam_bank_read_ptr[2])
return sam_bank_read_ptr[2][offset];
return 0xff;
}
WRITE8_MEMBER(samcoupe_state::sam_bank3_w)
{
if (sam_bank_write_ptr[2])
sam_bank_write_ptr[2][offset] = data;
}
READ8_MEMBER(samcoupe_state::sam_bank4_r)
{
if (sam_bank_read_ptr[3])
return sam_bank_read_ptr[3][offset];
return 0xff;
}
WRITE8_MEMBER(samcoupe_state::sam_bank4_w)
{
if (sam_bank_write_ptr[3])
sam_bank_write_ptr[3][offset] = data;
}
void samcoupe_state::samcoupe_update_bank(address_space &space, int bank_num, uint8_t *memory, int is_readonly)
{
sam_bank_read_ptr[bank_num-1] = memory;
if (!is_readonly)
sam_bank_write_ptr[bank_num-1] = memory;
else
sam_bank_write_ptr[bank_num-1] = nullptr;
// installing banks on the fly is too slow (20% speed in Manic Miner gameplay vs 300% speed)
#if 0
char bank[10];
sprintf(bank,"bank%d",bank_num);
if (memory)
{
membank(bank)->set_base(memory);
space.install_read_bank (((bank_num-1) * 0x4000), ((bank_num-1) * 0x4000) + 0x3FFF, bank);
if (is_readonly) {
space.unmap_write(((bank_num-1) * 0x4000), ((bank_num-1) * 0x4000) + 0x3FFF);
} else {
space.install_write_bank(((bank_num-1) * 0x4000), ((bank_num-1) * 0x4000) + 0x3FFF, bank);
}
} else {
space.nop_readwrite(((bank_num-1) * 0x4000), ((bank_num-1) * 0x4000) + 0x3FFF);
}
#endif
}
void samcoupe_state::samcoupe_install_ext_mem(address_space &space)
{
uint8_t *mem;
/* bank 3 */
if (m_lext >> 6 < m_ram->size() >> 20)
mem = &m_ram->pointer()[(m_ram->size() & 0xfffff) + (m_lext >> 6) * 0x100000 + (m_lext & 0x3f) * 0x4000];
else
mem = nullptr;
samcoupe_update_bank(space, 3, mem, false);
/* bank 4 */
if (m_hext >> 6 < m_ram->size() >> 20)
mem = &m_ram->pointer()[(m_ram->size() & 0xfffff) + (m_hext >> 6) * 0x100000 + (m_hext & 0x3f) * 0x4000];
else
mem = nullptr;
samcoupe_update_bank(space, 4, mem, false);
}
void samcoupe_state::samcoupe_update_memory(address_space &space)
{
const int page_mask = ((m_ram->size() & 0xfffff) / 0x4000) - 1;
uint8_t *rom = m_region_maincpu->base();
uint8_t *memory;
int is_readonly;
/* BANK1 */
if (m_lmpr & LMPR_RAM0) /* Is ram paged in at bank 1 */
{
if ((m_lmpr & 0x1F) <= page_mask)
memory = &m_ram->pointer()[(m_lmpr & page_mask) * 0x4000];
else
memory = nullptr; /* Attempt to page in non existant ram region */
is_readonly = false;
}
else
{
memory = rom; /* Rom0 paged in */
is_readonly = true;
}
samcoupe_update_bank(space, 1, memory, is_readonly);
/* BANK2 */
if (((m_lmpr + 1) & 0x1f) <= page_mask)
memory = &m_ram->pointer()[((m_lmpr + 1) & page_mask) * 0x4000];
else
memory = nullptr; /* Attempt to page in non existant ram region */
samcoupe_update_bank(space, 2, memory, false);
/* only update bank 3 and 4 when external memory is not enabled */
if (m_hmpr & HMPR_MCNTRL)
{
samcoupe_install_ext_mem(space);
}
else
{
/* BANK3 */
if ((m_hmpr & 0x1F) <= page_mask )
memory = &m_ram->pointer()[(m_hmpr & page_mask)*0x4000];
else
memory = nullptr; /* Attempt to page in non existant ram region */
samcoupe_update_bank(space, 3, memory, false);
/* BANK4 */
if (m_lmpr & LMPR_ROM1) /* Is Rom1 paged in at bank 4 */
{
memory = rom + 0x4000;
is_readonly = true;
}
else
{
if (((m_hmpr + 1) & 0x1f) <= page_mask)
memory = &m_ram->pointer()[((m_hmpr + 1) & page_mask) * 0x4000];
else
memory = nullptr; /* Attempt to page in non existant ram region */
is_readonly = false;
}
samcoupe_update_bank(space, 4, memory, false);
}
/* video memory location */
if (m_vmpr & 0x40) /* if bit set in 2 bank screen mode */
m_videoram = &m_ram->pointer()[((m_vmpr & 0x1e) & page_mask) * 0x4000];
else
m_videoram = &m_ram->pointer()[((m_vmpr & 0x1f) & page_mask) * 0x4000];
}
WRITE8_MEMBER(samcoupe_state::samcoupe_ext_mem_w)
{
address_space &space_program = m_maincpu->space(AS_PROGRAM);
if (offset & 1)
m_hext = data;
else
m_lext = data;
/* external RAM enabled? */
if (m_hmpr & HMPR_MCNTRL)
{
samcoupe_install_ext_mem(space_program);
}
}
/***************************************************************************
REAL TIME CLOCK
***************************************************************************/
READ8_MEMBER(samcoupe_state::samcoupe_rtc_r)
{
address_space &spaceio = m_maincpu->space(AS_IO);
return m_rtc->read(spaceio, offset >> 12);
}
WRITE8_MEMBER(samcoupe_state::samcoupe_rtc_w)
{
address_space &spaceio = m_maincpu->space(AS_IO);
m_rtc->write(spaceio, offset >> 12, data);
}
/***************************************************************************
MOUSE
***************************************************************************/
TIMER_CALLBACK_MEMBER(samcoupe_state::samcoupe_mouse_reset)
{
m_mouse_index = 0;
}
uint8_t samcoupe_state::samcoupe_mouse_r()
{
uint8_t result;
/* on a read, reset the timer */
m_mouse_reset->adjust(attotime::from_usec(50));
/* update when we are about to read the first real values */
if (m_mouse_index == 2)
{
/* update values */
int mouse_x = m_io_mouse_x->read();
int mouse_y = m_io_mouse_y->read();
int mouse_dx = m_mouse_x - mouse_x;
int mouse_dy = m_mouse_y - mouse_y;
m_mouse_x = mouse_x;
m_mouse_y = mouse_y;
/* button state */
m_mouse_data[2] = m_mouse_buttons->read();
/* y-axis */
m_mouse_data[3] = (mouse_dy & 0xf00) >> 8;
m_mouse_data[4] = (mouse_dy & 0x0f0) >> 4;
m_mouse_data[5] = (mouse_dy & 0x00f) >> 0;
/* x-axis */
m_mouse_data[6] = (mouse_dx & 0xf00) >> 8;
m_mouse_data[7] = (mouse_dx & 0x0f0) >> 4;
m_mouse_data[8] = (mouse_dx & 0x00f) >> 0;
}
/* get current value */
result = m_mouse_data[m_mouse_index++];
/* reset if we are at the end */
if (m_mouse_index == sizeof(m_mouse_data))
m_mouse_index = 1;
return result;
}
void samcoupe_state::machine_start()
{
m_mouse_reset = timer_alloc(TIMER_MOUSE_RESET);
/* schedule our video updates */
m_video_update_timer = timer_alloc(TIMER_VIDEO_UPDATE);
m_video_update_timer->adjust(m_screen->time_until_pos(0, 0));
}
/***************************************************************************
RESET
***************************************************************************/
void samcoupe_state::machine_reset()
{
address_space &space = m_maincpu->space(AS_PROGRAM);
address_space &spaceio = m_maincpu->space(AS_IO);
/* initialize state */
m_lmpr = 0x0f; /* ROM0 paged in, ROM1 paged out RAM Banks */
m_hmpr = 0x01;
m_vmpr = 0x81;
m_line_int = 0xff; /* line interrupts disabled */
m_status = 0x1f; /* no interrupts active */
/* initialize mouse */
m_mouse_index = 0;
m_mouse_data[0] = 0xff;
m_mouse_data[1] = 0xff;
if (m_config->read() & 0x01)
{
/* install RTC */
spaceio.install_readwrite_handler(0xef, 0xef, 0, 0, 0xff00, read8_delegate(FUNC(samcoupe_state::samcoupe_rtc_r),this), write8_delegate(FUNC(samcoupe_state::samcoupe_rtc_w),this));
}
else
{
/* no RTC support */
spaceio.unmap_readwrite(0xef, 0xef, 0xff00);
}
/* initialize memory */
samcoupe_update_memory(space);
}