// license:MAME|LGPL-2.1+
// copyright-holders:Michael Zapf
/******************************************************************************
    MESS Driver for the Myarc Geneve 9640.

    The Geneve has two operation modes.  One is compatible with the TI-99/4a,
    the other is not.


    General architecture:

    TMS9995@12MHz (including 256 bytes of on-chip 16-bit RAM and a timer),
    V9938, SN76496 (compatible with TMS9919), TMS9901, MM58274 RTC, 512 kbytes
    of 1-wait-state CPU RAM (expandable to almost 2 Mbytes), 32 kbytes of
    0-wait-state CPU RAM (expandable to 64 kbytes), 128 kbytes of VRAM
    (expandable to 192 kbytes).


    Memory map:

    64-kbyte CPU address space is mapped to a 2-Mbyte virtual address space.
    8 8-kbyte pages are available simultaneously, out of a total of 256.

    Page map (regular console):
    >00->3f: 512kbytes of CPU RAM (pages >36 and >37 are used to emulate
      cartridge CPU ROMs in ti99 mode, and pages >38 through >3f are used to
      emulate console and cartridge GROMs in ti99 mode)
    >40->7f: optional Memex RAM (except >7a and >7c that are mirrors of >ba and
      >bc?)
    >80->b7: PE-bus space using spare address lines (AMA-AMC)?  Used by RAM
        extension (Memex or PE-Bus 512k card).
    >b8->bf: PE-bus space (most useful pages are >ba: DSR space and >bc: speech
      synthesizer page; other pages are used by RAM extension)
    >c0->e7: optional Memex RAM
    >e8->ef: 64kbytes of 0-wait-state RAM (with 32kbytes of SRAM installed,
      only even pages (>e8, >ea, >ec and >ee) are available)
    >f0->f1: boot ROM
    >f2->fe: optional Memex RAM? (except >fa and >fc that are mirrors of >ba
      and >bc?)
    >ff: always empty?

    Page map (genmod console):
    >00->39, >40->b9, >bb, >bd->ef, f2->fe: Memex RAM (except >3a, >3c, >7a,
      >7c, >fa and >fc that are mirrors of >ba and >bc?) (I don't know if
      >e8->ef is on the Memex board or the Geneve motherboard)
    >ba: DSR space
    >bc: speech synthesizer space
    >f0->f1: boot ROM
    >ff: always empty?

    >00->3f: switch-selectable(?): 512kbytes of onboard RAM (1-wait-state DRAM)
      or first 512kbytes of the Memex Memory board (0-wait-state SRAM).  The
      latter setting is incompatible with TI mode.

    Note that >bc is actually equivalent to >8000->9fff on the /4a bus,
    therefore the speech synthesizer is only available at offsets >1800->1bff
    (read port) and >1c00->1fff (write port).  OTOH, if you installed a FORTI
    sound card, it will be available in the same page at offsets >0400->7ff.


    Unpaged locations (ti99 mode):
    >8000->8007: memory page registers (>8000 for page 0, >8001 for page 1,
      etc.  register >8003 is ignored (this page is hard-wired to >36->37).
    >8008: key buffer
    >8009->800f: ???
    >8010->801f: clock chip
    >8400->9fff: sound, VDP, speech, and GROM registers (according to one
      source, the GROM and sound registers are only available if page >3
      is mapped in at location >c000 (register 6).  I am not sure the Speech
      registers are implemented, though I guess they are.)
    Note that >8020->83ff is mapped to regular CPU RAM according to map
    register 4.

    Unpaged locations (native mode):
    >f100: VDP data port (read/write)
    >f102: VDP address/status port (read/write)
    >f104: VDP port 2
    >f106: VDP port 3
    >f108->f10f: VDP mirror (used by Barry Boone's converted Tomy cartridges)
    >f110->f117: memory page registers (>f110 for page 0, >f111 for page 1,
      etc.)
    >f118: key buffer
    >f119->f11f: ???
    >f120: sound chip
    >f121->f12f: ???
    >f130->f13f: clock chip

    Unpaged locations (tms9995 locations):
    >f000->f0fb and >fffc->ffff: tms9995 RAM
    >fffa->fffb: tms9995 timer register
    Note: accessing tms9995 locations will also read/write corresponding paged
      locations.


    GROM emulator:

    The GPL interface is accessible only in TI99 mode.  GPL data is fetched
    from pages >38->3f.  It uses a straight 16-bit address pointer.  The
    address pointer is incremented when the read data and write data ports
    are accessed, and when the second byte of the GPL address is written.  A
    weird consequence of this is the fact that GPL data is always off by one
    byte, i.e. GPL bytes 0, 1, 2... are stored in bytes 1, 2, 3... of pages
    >38->3f (byte 0 of page >38 corresponds to GPL address >ffff).

    I think that I have once read that the geneve GROM emulator does not
    emulate wrap-around within a GROM, i.e. address >1fff is followed by >2000
    (instead of >0000 with a real GROM).

    There are two ways to implement GPL address load and store.
    One is maintaining 2 flags (one for address read and one for address write)
    that tell if you are accessing address LSB: these flags must be cleared
    whenever data is read, and the read flag must be cleared when the write
    address port is written to.
    The other is to shift the register and always read/write the MSByte of the
    address pointer.  The LSByte is copied to the MSbyte when the address is
    read, whereas the former MSByte is copied to the LSByte when the address is
    written.  The address pointer must be incremented after the address is
    written to.  It will not harm if it is incremented after the address is
    read, provided the LSByte has been cleared.


    Cartridge emulator:

    The cartridge interface is in the >6000->7fff area.

    If CRU bit @>F7C is set, the cartridge area is always mapped to virtual
    page >36.  Writes in the >6000->6fff area are ignored if the CRU bit @>F7D
    is 0, whereas writes in the >7000->7fff area are ignored if the CRU bit
    @>F7E is 0.

    If CRU bit @>F7C is clear, the cartridge area is mapped either to virtual
    page >36 or to page >37 according to which page is currently selected.
    Writing data to address >6000->7fff will select page >36 if A14 is 0,
    >37 if A14 is 1.


    CRU map:

    Base >0000: tms9901
    tms9901 pin assignment:
    int1: external interrupt (INTA on PE-bus) (connected to tms9995 (int4/EC)*
      pin as well)
    int2: VDP interrupt
    int3-int7: joystick port inputs (fire, left, right, down, up)
    int8: keyboard interrupt (asserted when key buffer full)
    int9/p13: unused
    int10/p12: third mouse button
    int11/p11: clock interrupt?
    int12/p10: INTB from PE-bus
    int13/p9: (used as output)
    int14/p8: unused
    int15/p7: (used as output)
    p0: PE-bus reset line
    p1: VDP reset line
    p2: joystick select (0 for joystick 1, 1 for joystick 2)
    p3-p5: unused
    p6: keyboard reset line
    p7/int15: external mem cycles 0=long, 1=short
    p9/int13: vdp wait cycles 1=add 15 cycles, 0=add none

    Base >1EE0 (>0F70): tms9995 flags and geneve mode register
    bits 0-1: tms9995 flags
    Bits 2-4: tms9995 interrupt state register
    Bits 5-15: tms9995 user flags - overlaps geneve mode, but hopefully the
      geneve registers are write-only, so no real conflict happens
    TMS9995 user flags:
    Bit 5: 0 if NTSC, 1 if PAL video
    Bit 6: unused???
    Bit 7: some keyboard flag, set to 1 if caps is on
    Geneve gate array + TMS9995 user flags:
    Bit 8: 1 = allow keyboard clock
    Bit 9: 0 = clear keyboard input buffer, 1 = allow keyboard buffer to be
      loaded
    Bit 10: 1 = geneve mode, 0 = ti99 mode
    Bit 11: 1 = ROM mode, 0 = map mode
    Bit 12: 0 = Enable cartridge paging
    Bit 13: 0 = protect cartridge range >6000->6fff
    Bit 14: 0 = protect cartridge range >7000->7fff
    bit 15: 1 = add 1 extra wait state when accessing 0-wait-state SRAM???


    Keyboard interface:

    The XT keyboard interface is described in various places on the internet,
    like (http://www-2.cs.cmu.edu/afs/cs/usr/jmcm/www/info/key2.txt).  It is a
    synchronous unidirectional serial interface: the data line is driven by the
    keyboard to send data to the CPU; the CTS/clock line has a pull up resistor
    and can be driven low by both keyboard and CPU.  To send data to the CPU,
    the keyboard pulses the clock line low 9 times, and the Geneve samples all
    8 bits of data (plus one start bit) on each falling edge of the clock.
    When the key code buffer is full, the Geneve gate array asserts the kbdint*
    line (connected to 9901 INT8*).  The Geneve gate array will hold the
    CTS/clock line low as long as the keyboard buffer is full or CRU bit @>F78
    is 0.  Writing a 0 to >F79 will clear the Geneve keyboard buffer, and
    writing a 1 will resume normal operation: you need to write a 0 to >F78
    before clearing >F79, or the keyboard will be enabled to send data the gate
    array when >F79 is is set to 0, and any such incoming data from the
    keyboard will be cleared as soon as it is buffered by the gate array.

    Original version 2003 by Raphael Nabet

    Rewritten 2012 by Michael Zapf
******************************************************************************/


#include "emu.h"
#include "cpu/tms9900/tms9995.h"
#include "machine/tms9901.h"
#include "machine/mm58274c.h"
#include "sound/sn76496.h"

#include "machine/ti99/genboard.h"
#include "machine/ti99/peribox.h"
#include "machine/ti99/videowrp.h"

#include "machine/ti99/joyport.h"

#include "drivlgcy.h"

#define VERBOSE 1
#define LOG logerror

#define SRAM_SIZE 384*1024   // maximum SRAM expansion on-board
#define DRAM_SIZE 512*1024

class geneve_state : public driver_device
{
public:
	geneve_state(const machine_config &mconfig, device_type type, const char *tag)
		: driver_device(mconfig, type, tag) { }

	// CRU (Communication Register Unit) handling
	DECLARE_READ8_MEMBER(cruread);
	DECLARE_WRITE8_MEMBER(cruwrite);

	// Connections with the system interface TMS9901
	DECLARE_READ8_MEMBER(read_by_9901);
	DECLARE_WRITE_LINE_MEMBER(peripheral_bus_reset);
	DECLARE_WRITE_LINE_MEMBER(VDP_reset);
	DECLARE_WRITE_LINE_MEMBER(joystick_select);
	DECLARE_WRITE_LINE_MEMBER(extbus_wait_states);
	DECLARE_WRITE_LINE_MEMBER(video_wait_states);

	DECLARE_WRITE_LINE_MEMBER(clock_out);
	DECLARE_WRITE_LINE_MEMBER(dbin_line);

	DECLARE_WRITE8_MEMBER(external_operation);

	DECLARE_WRITE8_MEMBER(tms9901_interrupt);

	DECLARE_WRITE_LINE_MEMBER( keyboard_interrupt );

	geneve_keyboard_device* m_keyboard;
	geneve_mouse_device*    m_mouse;
	tms9901_device*         m_tms9901;
	geneve_mapper_device*   m_mapper;
	peribox_device*         m_peribox;
	tms9995_device*         m_cpu;
	joyport_device*         m_joyport;

	DECLARE_WRITE_LINE_MEMBER( inta );
	DECLARE_WRITE_LINE_MEMBER( intb );
	DECLARE_WRITE_LINE_MEMBER( ext_ready );
	DECLARE_WRITE_LINE_MEMBER( mapper_ready );

	DECLARE_DRIVER_INIT(geneve);
	virtual void machine_start();
	virtual void machine_reset();
	TIMER_DEVICE_CALLBACK_MEMBER(geneve_hblank_interrupt);

	DECLARE_WRITE_LINE_MEMBER(set_tms9901_INT2_from_v9938);

	line_state  m_inta;
	line_state  m_intb;
	line_state  m_int2;
	line_state  m_keyint;
	line_state  m_video_wait; // reflects the line to the mapper for CRU query

	int m_ready_line, m_ready_line1;

private:
	//int     m_joystick_select;
	// Some values to keep. Rest is on the geneve_mapper.
};

/*
    Memory map
*/

static ADDRESS_MAP_START(memmap, AS_PROGRAM, 8, geneve_state)
	AM_RANGE(0x0000, 0xffff) AM_DEVREADWRITE(GMAPPER_TAG, geneve_mapper_device, readm, writem) AM_DEVSETOFFSET(GMAPPER_TAG, geneve_mapper_device, setoffset)
ADDRESS_MAP_END

/*
    CRU map
    The TMS9901 is fully decoded, no mirroring, so we have 32 bits for it,
    and the rest goes to the board (and from there to the PEB)
    TMS9995 has a full 15-bit CRU bit address space (attached to A0-A14)
    TODO: Check whether A0-A2 are available for CRU addressing since those
    bits are usually routed through the mapper first.
*/
static ADDRESS_MAP_START(crumap, AS_IO, 8, geneve_state)
	AM_RANGE(0x0000, 0x0003) AM_DEVREAD(TMS9901_TAG, tms9901_device, read)
	AM_RANGE(0x0000, 0x0fff) AM_READ( cruread )

	AM_RANGE(0x0000, 0x001f) AM_DEVWRITE(TMS9901_TAG, tms9901_device, write)
	AM_RANGE(0x0000, 0x7fff) AM_WRITE( cruwrite )
ADDRESS_MAP_END

/* TI joysticks. The keyboard is implemented in genboard.c. */
static INPUT_PORTS_START(geneve)

	PORT_START( "MODE" )
	PORT_CONFNAME( 0x01, 0x00, "Operating mode" ) PORT_CHANGED_MEMBER(PERIBOX_TAG, peribox_device, genmod_changed, 0)
		PORT_CONFSETTING(    0x00, "Standard" )
		PORT_CONFSETTING(    GENMOD, "GenMod" )

	PORT_START( "BOOTROM" )
	PORT_CONFNAME( 0x01, GENEVE_098, "Boot ROM" ) PORT_CONDITION( "MODE", 0x01, EQUALS, 0x00 )
		PORT_CONFSETTING( GENEVE_098, "Version 0.98" )
		PORT_CONFSETTING( GENEVE_100, "Version 1.00" )

	PORT_START( "SRAM" )
	PORT_CONFNAME( 0x03, 0x01, "Onboard SRAM" ) PORT_CONDITION( "MODE", 0x01, EQUALS, 0x00 )
		PORT_CONFSETTING( 0x00, "32 KiB" )
		PORT_CONFSETTING( 0x01, "64 KiB" )
		PORT_CONFSETTING( 0x02, "384 KiB" )

	PORT_START( "GENMODDIPS" )
	PORT_DIPNAME( GM_TURBO, 0x00, "Genmod Turbo mode") PORT_CONDITION( "MODE", 0x01, EQUALS, GENMOD ) PORT_CHANGED_MEMBER(GMAPPER_TAG, geneve_mapper_device, gm_changed, 1)
		PORT_CONFSETTING( 0x00, DEF_STR( Off ))
		PORT_CONFSETTING( GM_TURBO, DEF_STR( On ))
	PORT_DIPNAME( GM_TIM, GM_TIM, "Genmod TI mode") PORT_CONDITION( "MODE", 0x01, EQUALS, GENMOD ) PORT_CHANGED_MEMBER(GMAPPER_TAG, geneve_mapper_device, gm_changed, 2)
		PORT_CONFSETTING( 0x00, DEF_STR( Off ))
		PORT_CONFSETTING( GM_TIM, DEF_STR( On ))

INPUT_PORTS_END

/****************************************************************************
    CRU handling
*****************************************************************************/

#define CRU_CONTROL_BASE 0x1ee0
#define CRU_SSTEP_BASE 0x13c0

WRITE8_MEMBER ( geneve_state::cruwrite )
{
	int addroff = offset << 1;

	// Single step
	// 13c0 - 13fe: 0001 0011 11xx xxx0
	if ((addroff & 0xffc0) == CRU_SSTEP_BASE)
	{
		int bit = (addroff & 0x003e)>>1;
		if (VERBOSE>0) LOG("geneve: Single step not implemented; bit %d set to %d\n", bit, data);
		return;
	}

	if ((addroff & 0xffe0) == CRU_CONTROL_BASE)
	{
		int bit = (addroff & 0x001e)>>1;
		switch (bit)
		{
		case 5:
			// No one really cares...
			if (VERBOSE>8) LOG("geneve: Set PAL flag = %02x\n", data);
			// m_palvideo = (data!=0);
			break;
		case 7:
			// m_capslock = (data!=0);
			if (VERBOSE>8) LOG("geneve: Set capslock flag = %02x\n", data);
			break;
		case 8:
			if (VERBOSE>8) LOG("geneve: Set keyboard clock flag = %02x\n", data);
			m_keyboard->clock_control((data!=0)? ASSERT_LINE : CLEAR_LINE);
			break;
		case 9:
			if (VERBOSE>8) LOG("geneve: Set keyboard scan flag = %02x\n", data);
			m_keyboard->send_scancodes((data!=0)? ASSERT_LINE : CLEAR_LINE);
			break;
		case 10:
			if (VERBOSE>8) LOG("geneve: Geneve mode = %02x\n", data);
			m_mapper->set_geneve_mode(data!=0);
			break;
		case 11:
			if (VERBOSE>8) LOG("geneve: Direct mode = %02x\n", data);
			m_mapper->set_direct_mode(data!=0);
			break;
		case 12:
			if (VERBOSE>8) LOG("geneve: Cartridge size 8K = %02x\n", data);
			m_mapper->set_cartridge_size((data!=0)? 0x2000 : 0x4000);
			break;
		case 13:
			if (VERBOSE>8) LOG("geneve: Cartridge writable 6000 = %02x\n", data);
			m_mapper->set_cartridge_writable(0x6000, (data!=0));
			break;
		case 14:
			if (VERBOSE>8) LOG("geneve: Cartridge writable 7000 = %02x\n", data);
			m_mapper->set_cartridge_writable(0x7000, (data!=0));
			break;
		case 15:
			if (VERBOSE>8) LOG("geneve: Extra wait states = %02x\n", data==0);
			m_mapper->set_extra_waitstates(data==0);  // let's use the inverse semantics
			break;
		default:
			if (VERBOSE>0) LOG("geneve: set CRU address %04x=%02x ignored\n", addroff, data);
			break;
		}
	}
	else
	{
		m_peribox->cruwrite(space, addroff, data);
	}
}

READ8_MEMBER( geneve_state::cruread )
{
	UINT8 value = 0;
	int addroff = offset << 4;

	// Single step
	// 13c0 - 13fe: 0001 0011 11xx xxx0
	if ((addroff & 0xffc0) == CRU_SSTEP_BASE)
	{
		int bit = (addroff & 0x003e)>>1;
		if (VERBOSE>0) LOG("geneve: Single step not implemented; attempting to read bit %d\n", bit);
		return value;
	}

	// TMS9995-internal CRU locations (1ee0-1efe) are handled within the processor
	// so we just don't arrive here

	// Propagate the CRU access to external devices
	m_peribox->crureadz(space, addroff, &value);
	return value;
}

/***********************************************************************
    CRU callbacks
***********************************************************************/

READ8_MEMBER( geneve_state::read_by_9901 )
{
	int answer = 0;

	switch (offset & 0x03)
	{
	case TMS9901_CB_INT7:
		//
		// Read pins INT3*-INT7* of Geneve's 9901.
		// bit 1: INTA status
		// bit 2: INT2 status
		// bit 3-7: joystick status
		//
		// |K|K|K|K|K|I2|I1|C|
		// negative logic
		if (m_inta==CLEAR_LINE) answer |= 0x02;
		if (m_int2==CLEAR_LINE) answer |= 0x04;
		answer |= m_joyport->read_port()<<3;
		break;

	case TMS9901_INT8_INT15:
		// Read pins INT8*-INT15* of Geneve 9901.
		//
		// bit 0: keyboard interrupt
		// bit 1: unused
		// bit 2: mouse left button
		// (bit 3: clock interrupt)
		// bit 4: INTB from PE-bus
		// bit 5 & 7: used as output
		// bit 6: unused
		if (m_keyint==CLEAR_LINE) answer |= 0x01;
		if (m_mouse->left_button()==CLEAR_LINE) answer |= 0x04;
		// TODO: add clock interrupt
		if (m_intb==CLEAR_LINE) answer |= 0x10;
		if (m_video_wait==ASSERT_LINE) answer |= 0x20;
		// TODO: PAL pin 5
		if (VERBOSE>8) LOG("geneve: INT15-8 = %02x\n", answer);
		break;

	case TMS9901_P0_P7:
		// Read pins P0-P7 of TMS9901. All pins are configured as outputs, so nothing here.
		break;

	case TMS9901_P8_P15:
		// Read pins P8-P15 of TMS 9901.
		// bit 4: mouse left button
		// video wait is an output; no input possible here
		if (m_intb==CLEAR_LINE) answer |= 0x04;     // mirror from above
		// TODO: 0x08 = real-time clock int
		if (m_mouse->left_button()==CLEAR_LINE) answer |= 0x10; // mirror from above
		if (m_keyint==CLEAR_LINE) answer |= 0x40;

		// Joystick up (mirror of bit 7)
		if ((m_joyport->read_port() & 0x10)==0) answer |= 0x80;
		break;
	}
	return answer;
}

/*
    Write PE bus reset line
*/
WRITE_LINE_MEMBER( geneve_state::peripheral_bus_reset )
{
	if (VERBOSE>0) LOG("geneve: peripheral bus reset request; not implemented yet.\n");
}

/*
    Write VDP reset line
*/
WRITE_LINE_MEMBER( geneve_state::VDP_reset )
{
	if (VERBOSE>0) LOG("geneve: Video reset request; not implemented yet.\n");
}

/*
    Write joystick select line. 1 selects joystick 1 (pin 7), 0 selects joystick 2 (pin 2)
*/
WRITE_LINE_MEMBER( geneve_state::joystick_select )
{
	m_joyport->write_port((state==ASSERT_LINE)? 1:2);
}

/*
    Write external mem cycles (0=long, 1=short)
*/
WRITE_LINE_MEMBER( geneve_state::extbus_wait_states )
{
	if (VERBOSE>0) LOG("geneve: external bus wait states set to %d, not implemented yet.\n", state);
}

/*
    Write vdp wait cycles (1=add 14 cycles, 0=add none)
    see above for waitstate handling
*/
WRITE_LINE_MEMBER( geneve_state::video_wait_states )
{
	if (VERBOSE>1) LOG("geneve: video wait states set to %d\n", state);
	m_mapper->set_video_waitstates(state==ASSERT_LINE);
	m_video_wait = (state!=0)? ASSERT_LINE : CLEAR_LINE;
}

/*
    Called by the 9901 core whenever the state of INTREQ and IC0-3 changes.
    As with the TI-99/4A, the interrupt level is delivered as the offset,
    but again it is ignored. Anyway, the TMS9995 has only two external inputs
    (INT1 and INT4).
*/
WRITE8_MEMBER( geneve_state::tms9901_interrupt )
{
	/* INTREQ is connected to INT1. */
	m_cpu->set_input_line(INT_9995_INT1, data);
}

/* tms9901 setup */
const tms9901_interface tms9901_wiring_geneve =
{
	TMS9901_INT1 | TMS9901_INT2 | TMS9901_INT8 | TMS9901_INTB | TMS9901_INTC,   /* only input pins whose state is always known */

	// read handler
	DEVCB_DRIVER_MEMBER(geneve_state, read_by_9901),

	{   /* write handlers */
		DEVCB_DRIVER_LINE_MEMBER(geneve_state, peripheral_bus_reset),
		DEVCB_DRIVER_LINE_MEMBER(geneve_state, VDP_reset),
		DEVCB_DRIVER_LINE_MEMBER(geneve_state, joystick_select),
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_DEVICE_LINE_MEMBER(GKEYBOARD_TAG, geneve_keyboard_device, reset_line),
		DEVCB_DRIVER_LINE_MEMBER(geneve_state, extbus_wait_states),
		DEVCB_NULL,
		DEVCB_DRIVER_LINE_MEMBER(geneve_state, video_wait_states),
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_NULL,
		DEVCB_NULL
	},

	/* interrupt handler */
	DEVCB_DRIVER_MEMBER(geneve_state, tms9901_interrupt)
};

/*******************************************************************
    Signal lines
*******************************************************************/
/*
    inta is connected to both tms9901 IRQ1 line and to tms9995 INT4/EC line.
*/
WRITE_LINE_MEMBER( geneve_state::inta )
{
	m_inta = (state!=0)? ASSERT_LINE : CLEAR_LINE;
	m_tms9901->set_single_int(1, state);
	m_cpu->set_input_line(INT_9995_INT4, state);
}

/*
    intb is connected to tms9901 IRQ12 line.
*/
WRITE_LINE_MEMBER( geneve_state::intb )
{
	m_intb = (state!=0)? ASSERT_LINE : CLEAR_LINE;
	m_tms9901->set_single_int(12, state);
}

WRITE_LINE_MEMBER( geneve_state::ext_ready )
{
	if (VERBOSE>6) LOG("geneve: READY level (ext) = %02x\n", state);
	m_ready_line = state;
	m_cpu->set_ready((m_ready_line == ASSERT_LINE && m_ready_line1 == ASSERT_LINE)? ASSERT_LINE : CLEAR_LINE);
}

WRITE_LINE_MEMBER( geneve_state::mapper_ready )
{
	if (VERBOSE>6) LOG("geneve: READY level (mapper) = %02x\n", state);
	m_ready_line1 = state;
	m_cpu->set_ready((m_ready_line == ASSERT_LINE && m_ready_line1 == ASSERT_LINE)? ASSERT_LINE : CLEAR_LINE);
}

/*
    set the state of int2 (called by the v9938 core)
*/
WRITE_LINE_MEMBER(geneve_state::set_tms9901_INT2_from_v9938)
{
	m_int2 = (state!=0)? ASSERT_LINE : CLEAR_LINE;
	m_tms9901->set_single_int(2, state);
}

/*
    Interrupt from the keyboard.
*/
WRITE_LINE_MEMBER( geneve_state::keyboard_interrupt )
{
	m_keyint = (state!=0)? ASSERT_LINE : CLEAR_LINE;
	m_tms9901->set_single_int(8, state);
}

/*
    scanline interrupt
*/
TIMER_DEVICE_CALLBACK_MEMBER(geneve_state::geneve_hblank_interrupt)
{
	int scanline = param;

	machine().device<v9938_device>(VDP_TAG)->interrupt();

	if (scanline == 0) // was 262
	{
		// TODO
		// The technical docs do not say anything about the way the mouse
		// is queried. It sounds plausible that the mouse is sampled once
		// per vertical interrupt; however, the mouse sometimes shows jerky
		// behaviour. Maybe we should use an autonomous timer with a higher
		// rate? -> to be checked
		m_mouse->poll();
	}
}

WRITE8_MEMBER( geneve_state::external_operation )
{
	static const char* extop[8] = { "inv1", "inv2", "IDLE", "RSET", "inv3", "CKON", "CKOF", "LREX" };
	if (VERBOSE>1)
		if (offset != IDLE_OP) LOG("geneve: External operation %s not implemented on Geneve board\n", extop[offset]);
}

/*
    Clock line from the CPU. Used to control wait state generation.
*/
WRITE_LINE_MEMBER( geneve_state::clock_out )
{
	m_mapper->clock_in(state);
}

/*
    DBIN line from the CPU. Used to control wait state generation.
*/
WRITE_LINE_MEMBER( geneve_state::dbin_line )
{
	m_mapper->dbin_in(state);
}

static TMS9995_CONFIG( geneve_processor_config )
{
	DEVCB_DRIVER_MEMBER(geneve_state, external_operation),
	DEVCB_NULL,         // Instruction acquisition
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, clock_out),
	DEVCB_NULL,         // HOLDA
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, dbin_line),      // DBIN
	INTERNAL_RAM,       // use internal RAM
	NO_OVERFLOW_INT     // The generally available versions of TMS9995 have a deactivated overflow interrupt
};

static TI_SOUND_CONFIG( sound_conf )
{
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, ext_ready)   // READY
};

static const mm58274c_interface geneve_mm58274c_interface =
{
	1,  /*  mode 24*/
	0   /*  first day of week */
};

static GENEVE_KEYBOARD_CONFIG( geneve_keyb_conf )
{
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, keyboard_interrupt)
};

static PERIBOX_CONFIG( peribox_conf )
{
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, inta),           // INTA
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, intb),           // INTB
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, ext_ready),  // READY
	0x00000                                         // Address bus prefix (Mapper will produce prefixes)
};

static GENEVE_MAPPER_CONFIG( mapper_conf )
{
	DEVCB_DRIVER_LINE_MEMBER(geneve_state, mapper_ready)    // READY
};

static JOYPORT_CONFIG( joyport_60 )
{
	DEVCB_NULL,
	60
};

DRIVER_INIT_MEMBER(geneve_state,geneve)
{
}

void geneve_state::machine_start()
{
	m_tms9901 = static_cast<tms9901_device*>(machine().device(TMS9901_TAG));
	m_mapper = static_cast<geneve_mapper_device*>(machine().device(GMAPPER_TAG));
	m_keyboard = static_cast<geneve_keyboard_device*>(machine().device(GKEYBOARD_TAG));
	m_peribox = static_cast<peribox_device*>(machine().device(PERIBOX_TAG));
	m_mouse =  static_cast<geneve_mouse_device*>(machine().device(GMOUSE_TAG));
	m_cpu = static_cast<tms9995_device*>(machine().device("maincpu"));
	m_joyport = static_cast<joyport_device*>(machine().device(JOYPORT_TAG));
}

/*
    Reset the machine.
*/
void geneve_state::machine_reset()
{
	m_inta = CLEAR_LINE;    // flag reflecting the INTA line
	m_intb = CLEAR_LINE;    // flag reflecting the INTB line
	m_int2 = CLEAR_LINE;    // flag reflecting the INT2 line
	m_keyint = CLEAR_LINE;

	// No automatic wait state (auto wait state is enabled with READY=CLEAR at RESET)
	m_cpu->set_ready(ASSERT_LINE);
	m_cpu->set_hold(CLEAR_LINE);

	m_ready_line = m_ready_line1 = ASSERT_LINE;

	m_peribox->set_genmod(ioport("MODE")->read()==GENMOD);

	m_joyport->write_port(0x01);    // select Joystick 1
}

static MACHINE_CONFIG_START( geneve_60hz, geneve_state )
	// basic machine hardware
	// TMS9995 CPU @ 12.0 MHz
	MCFG_TMS99xx_ADD("maincpu", TMS9995, 12000000, memmap, crumap, geneve_processor_config)

	// video hardware
	// Although we should have a 60 Hz screen rate, we have to set it to 30 here.
	// The reason is that that the number of screen lines is counted twice for the
	// interlace mode, but in non-interlace modes only half of the lines are
	// painted. Accordingly, the full set of lines is refreshed at 30 Hz,
	// not 60 Hz. This should be fixed in the v9938 emulation.
	MCFG_TI_V9938_ADD(VIDEO_SYSTEM_TAG, 30, SCREEN_TAG, 2500, 512+32, (212+28)*2, geneve_state, set_tms9901_INT2_from_v9938)
	MCFG_TIMER_DRIVER_ADD_SCANLINE("scantimer", geneve_state, geneve_hblank_interrupt, SCREEN_TAG, 0, 1) /* 262.5 in 60Hz, 312.5 in 50Hz */

	// Main board components
	MCFG_TMS9901_ADD(TMS9901_TAG, tms9901_wiring_geneve, 3000000)
	MCFG_GENEVE_MAPPER_ADD(GMAPPER_TAG, mapper_conf)
	MCFG_MM58274C_ADD(GCLOCK_TAG, geneve_mm58274c_interface)

	// Peripheral expansion box (Geneve composition)
	MCFG_PERIBOX_GEN_ADD( PERIBOX_TAG, peribox_conf )

	// sound hardware
	MCFG_TI_SOUND_76496_ADD( TISOUND_TAG, sound_conf )

	// User interface devices
	MCFG_GENEVE_KEYBOARD_ADD( GKEYBOARD_TAG, geneve_keyb_conf )
	MCFG_GENEVE_MOUSE_ADD( GMOUSE_TAG )
	MCFG_GENEVE_JOYPORT_ADD( JOYPORT_TAG, joyport_60 )

MACHINE_CONFIG_END

/*
    ROM loading
*/

ROM_START(geneve)
	/*CPU memory space*/
	ROM_REGION(0xc000, "maincpu", 0)
	ROM_LOAD("genbt100.bin", 0x0000, 0x4000, CRC(8001e386) SHA1(b44618b54dabac3882543e18555d482b299e0109)) /* CPU ROMs v1.0 */
	ROM_LOAD_OPTIONAL("genbt098.bin", 0x4000, 0x4000, CRC(b2e20df9) SHA1(2d5d09177afe97d63ceb3ad59b498b1c9e2153f7)) /* CPU ROMs v0.98 */
	ROM_LOAD_OPTIONAL("gnmbt100.bin", 0x8000, 0x4000, CRC(19b89479) SHA1(6ef297eda78dc705946f6494e9d7e95e5216ec47)) /* CPU ROMs GenMod */

	ROM_REGION(SRAM_SIZE, SRAM_TAG, 0)
	ROM_FILL(0x0000, SRAM_SIZE, 0)

	ROM_REGION(DRAM_SIZE, DRAM_TAG, 0)
	ROM_FILL(0x0000, DRAM_SIZE, 0)
ROM_END

/*    YEAR  NAME      PARENT    COMPAT  MACHINE      INPUT    INIT       COMPANY     FULLNAME */
COMP( 1987,geneve,   0,     0,      geneve_60hz,  geneve, geneve_state,  geneve,        "Myarc",    "Geneve 9640" , 0)
