

#include "includes/kaypro.h"




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

    PIO

    Port B is unused on both PIOs

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

WRITE_LINE_MEMBER( kaypro_state::write_centronics_busy )
{
	m_centronics_busy = state;
}

READ8_MEMBER( kaypro_state::pio_system_r )
{
	UINT8 data = 0;

	/* centronics busy */
	data |= m_centronics_busy << 3;

	/* PA7 is pulled high */
	data |= 0x80;

	return data;
}

WRITE8_MEMBER( kaypro_state::kayproii_pio_system_w )
{
/*  d7 bank select
    d6 disk drive motors - (0=on)
    d5 double-density enable (0=double density)
    d4 Centronics strobe
    d2 side select (1=side 1)
    d1 drive B
    d0 drive A */

	membank("bankr0")->set_entry(BIT(data, 7));
	membank("bank3")->set_entry(BIT(data, 7));
	m_is_motor_off = BIT(data, 6);

	m_floppy = NULL;
	if (BIT(data, 0))
		m_floppy = m_floppy0->get_device();
	else
	if (BIT(data, 1))
		m_floppy = m_floppy1->get_device();

	m_fdc->set_floppy(m_floppy);
	m_fdc->dden_w(BIT(data, 5));

	if (m_floppy)
	{
		m_floppy->mon_w(BIT(data, 6)); // motor on
		m_floppy->ss_w(!BIT(data, 2)); // signal exists even though drives are single sided
	}

	output_set_value("ledA", BIT(data, 0));     /* LEDs in artwork */
	output_set_value("ledB", BIT(data, 1));

	m_centronics->write_strobe(BIT(data, 4));

	m_system_port = data;
}

WRITE8_MEMBER( kaypro_state::kaypro4_pio_system_w )
{
	kayproii_pio_system_w(space, offset, data);

	/* side select */
	m_floppy->ss_w(BIT(data, 2));
}

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

    KAYPRO2X SYSTEM PORT

    The PIOs were replaced by a few standard 74xx chips

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

READ8_MEMBER( kaypro_state::kaypro2x_system_port_r )
{
	UINT8 data = m_centronics_busy << 6;
	return (m_system_port & 0xbf) | data;
}

WRITE8_MEMBER( kaypro_state::kaypro2x_system_port_w )
{
/*  d7 bank select
    d6 alternate character set (write only)
    d5 double-density enable
    d4 disk drive motors (1=on)
    d3 Centronics strobe
    d2 side select (appears that 0=side 1?)
    d1 drive B
    d0 drive A */

	membank("bankr0")->set_entry(BIT(data, 7));
	membank("bank3")->set_entry(BIT(data, 7));
	m_is_motor_off = !BIT(data, 4);

	m_floppy = NULL;
	if (!BIT(data, 0))
		m_floppy = m_floppy0->get_device();
	else
	if (!BIT(data, 1))
		m_floppy = m_floppy1->get_device();

	m_fdc->set_floppy(m_floppy);
	m_fdc->dden_w(BIT(data, 5));

	if (m_floppy)
	{
		m_floppy->mon_w(!BIT(data, 4)); // motor on
		m_floppy->ss_w(!BIT(data, 2));
	}

	output_set_value("ledA", BIT(data, 0));     /* LEDs in artwork */
	output_set_value("ledB", BIT(data, 1));

	m_centronics->write_strobe(BIT(data, 3));

	m_system_port = data;
}


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

    SIO

    On Kaypro2x, Channel B on both SIOs is hardwired to 300 baud.

    Both devices on sio2 (printer and modem) are not emulated.

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

/* Set baud rate. bits 0..3 Rx and Tx are tied together. Baud Rate Generator is a AY-5-8116, SMC8116, WD1943, etc.
    00h    50
    11h    75
    22h    110
    33h    134.5
    44h    150
    55h    300
    66h    600
    77h    1200
    88h    1800
    99h    2000
    AAh    2400
    BBh    3600
    CCh    4800
    DDh    7200
    EEh    9600
    FFh    19200 */


READ8_MEMBER(kaypro_state::kaypro_sio_r)
{
	if (offset == 1)
		return kay_kbd_d_r(machine());
	else
	if (offset == 3)
		return kay_kbd_c_r(machine());
	else
		return m_sio->cd_ba_r(space, offset);
}

WRITE8_MEMBER(kaypro_state::kaypro_sio_w)
{
	if (offset == 1)
		kay_kbd_d_w(machine(), data);
	else
		m_sio->cd_ba_w(space, offset, data);
}


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

    Floppy DIsk

    If DRQ or IRQ is set, and cpu is halted, the NMI goes low.
    Since the HALT occurs last (and has no callback mechanism), we need to set
    a short delay, to give time for the processor to execute the HALT before NMI
    becomes active.

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

void kaypro_state::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
{
	bool halt;
	switch (id)
	{
	case TIMER_FLOPPY:
		halt = (bool)m_maincpu->state_int(Z80_HALT);
		if (m_is_motor_off)
		{
			timer_set(attotime::from_hz(10), TIMER_FLOPPY);
			break;
		}
		if ((halt) && (m_fdc_rq & 3) && (m_fdc_rq < 0x80))
		{
			m_maincpu->set_input_line(INPUT_LINE_NMI, ASSERT_LINE);
			m_fdc_rq |= 0x80;
		}
		else
		if ((m_fdc_rq == 0x80) || ((!halt) && BIT(m_fdc_rq, 7)))
		{
			m_maincpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE);
			m_fdc_rq &= 0x7f;
		}
		timer_set(attotime::from_hz(1e5), TIMER_FLOPPY);

		break;
	default:
		assert_always(FALSE, "Unknown id in kaypro_state::device_timer");
	}
}

WRITE_LINE_MEMBER( kaypro_state::fdc_intrq_w )
{
	m_fdc_rq = (m_fdc_rq & 0x82) | state;
}

WRITE_LINE_MEMBER( kaypro_state::fdc_drq_w )
{
	m_fdc_rq = (m_fdc_rq & 0x81) | (state << 1);
}


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

    Machine

************************************************************/
MACHINE_START_MEMBER( kaypro_state,kayproii )
{
	m_pio_s->strobe_a(0);
}

MACHINE_RESET_MEMBER( kaypro_state,kaypro )
{
	MACHINE_RESET_CALL_MEMBER(kay_kbd);
	membank("bankr0")->set_entry(1); // point at rom
	membank("bankw0")->set_entry(0); // always write to ram
	membank("bank3")->set_entry(1); // point at video ram
	m_system_port = 0x80;
	m_fdc_rq = 0;
	m_maincpu->reset();
	timer_set(attotime::from_hz(1), TIMER_FLOPPY);   /* kick-start the nmi timer */
}


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

    Quickload

    This loads a .COM file to address 0x100 then jumps
    there. Sometimes .COM has been renamed to .CPM to
    prevent windows going ballistic. These can be loaded
    as well.

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

QUICKLOAD_LOAD_MEMBER( kaypro_state, kaypro )
{
	UINT8 *RAM = memregion("rambank")->base();
	UINT16 i;
	UINT8 data;

	/* Load image to the TPA (Transient Program Area) */
	for (i = 0; i < quickload_size; i++)
	{
		if (image.fread( &data, 1) != 1) return IMAGE_INIT_FAIL;

		RAM[i+0x100] = data;
	}

	membank("bankr0")->set_entry(0);
	membank("bank3")->set_entry(0);
	RAM[0x80]=0;                            // clear out command tail
	RAM[0x81]=0;
	m_maincpu->set_pc(0x100);                // start program
	return IMAGE_INIT_PASS;
}
