beta.cpp

// license:BSD-3-Clause
// copyright-holders:Curt Coder
/***************************************************************************

    Beta Computer

    http://retro.hansotten.nl/index.php?page=beta-computer

    When first started, press G to begin.

    Pasting:
        0-F : as is
        M (inc) : ^
        AD : -
        DA : =
        GO : X

    Test Paste:
        X-0011=11^22^33^44^55^66^77^88^99^-0011
        Now press M to confirm the data has been entered.

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

/*

    TODO:

    - verify whether feeding a 0xff-filled 2K binary file as cart allows
      to write back correctly EPROM or not

*/

#include "emu.h"

#include "cpu/m6502/m6502.h"
#include "imagedev/floppy.h"
#include "machine/mos6530.h"
#include "machine/ram.h"
#include "sound/spkrdev.h"

#include "bus/generic/slot.h"
#include "bus/generic/carts.h"

#include "speaker.h"

#include "beta.lh"


namespace {

#define SCREEN_TAG      "screen"
#define M6502_TAG       "m6502"
#define M6532_TAG       "m6532"
#define EPROM_TAG       "eprom"
//#define SPEAKER_TAG       "b237"

class beta_state : public driver_device
{
public:
	beta_state(const machine_config &mconfig, device_type type, const char *tag) :
		driver_device(mconfig, type, tag),
		m_maincpu(*this, M6502_TAG),
		m_speaker(*this, "speaker"),
		m_eprom(*this, EPROM_TAG),
		m_q(*this, "Q%u", 6U),
		m_digits(*this, "digit%u", 0U),
		m_leds(*this, "led%u", 0U)
	{ }

	DECLARE_INPUT_CHANGED_MEMBER( trigger_reset );
	void beta(machine_config &config);

protected:
	virtual void machine_start() override;

	uint8_t riot_pa_r();
	void riot_pa_w(uint8_t data);
	uint8_t riot_pb_r();
	void riot_pb_w(uint8_t data);

	DECLARE_DEVICE_IMAGE_LOAD_MEMBER(load_beta_eprom);
	DECLARE_DEVICE_IMAGE_UNLOAD_MEMBER(unload_beta_eprom);

	TIMER_CALLBACK_MEMBER(led_refresh);

	void beta_mem(address_map &map);

private:
	required_device<cpu_device> m_maincpu;
	required_device<speaker_sound_device> m_speaker;
	required_device<generic_slot_device> m_eprom;
	required_ioport_array<4> m_q;
	output_finder<6> m_digits;
	output_finder<2> m_leds;

	/* EPROM state */
	int m_eprom_oe = 0;
	int m_eprom_ce = 0;
	uint16_t m_eprom_addr = 0;
	uint8_t m_eprom_data = 0;
	uint8_t m_old_data = 0;
	std::vector<uint8_t> m_eprom_rom{};

	/* display state */
	uint8_t m_ls145_p = 0;
	uint8_t m_segment = 0;

	emu_timer *m_led_refresh_timer = nullptr;
};


/* Memory Maps */

void beta_state::beta_mem(address_map &map)
{
	map(0x0000, 0x007f).mirror(0x7f00).m(M6532_TAG, FUNC(mos6532_device::ram_map));
	map(0x0080, 0x00ff).mirror(0x7f00).m(M6532_TAG, FUNC(mos6532_device::io_map));
	map(0x8000, 0x87ff).mirror(0x7800).rom();
}

/* Input Ports */

INPUT_CHANGED_MEMBER( beta_state::trigger_reset )
{
	m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? CLEAR_LINE : ASSERT_LINE);
}

static INPUT_PORTS_START( beta )
	PORT_START("Q6")
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_A) PORT_CHAR('A')
	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_1) PORT_CHAR('1')
	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_4) PORT_CHAR('4')
	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_7) PORT_CHAR('7')
	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("GO") PORT_CODE(KEYCODE_G) PORT_CODE(KEYCODE_X) PORT_CHAR('X')
	PORT_BIT( 0xe0, IP_ACTIVE_LOW, IPT_UNUSED )

	PORT_START("Q7")
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_0) PORT_CHAR('0')
	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_2) PORT_CHAR('2')
	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_5) PORT_CHAR('5')
	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_8) PORT_CHAR('8')
	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_M) PORT_CODE(KEYCODE_UP) PORT_CHAR('^')
	PORT_BIT( 0xe0, IP_ACTIVE_LOW, IPT_UNUSED )

	PORT_START("Q8")
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_B) PORT_CHAR('B')
	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_3) PORT_CHAR('3')
	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_6) PORT_CHAR('6')
	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_9) PORT_CHAR('9')
	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("DA") PORT_CODE(KEYCODE_EQUALS) PORT_CHAR('=')
	PORT_BIT( 0xe0, IP_ACTIVE_LOW, IPT_UNUSED )

	PORT_START("Q9")
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_C) PORT_CHAR('C')
	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_D) PORT_CHAR('D')
	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_E) PORT_CHAR('E')
	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_F) PORT_CHAR('F')
	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("AD") PORT_CODE(KEYCODE_MINUS) PORT_CHAR('-')
	PORT_BIT( 0xe0, IP_ACTIVE_LOW, IPT_UNUSED )

	PORT_START("SPECIAL")
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("RESET") PORT_CODE(KEYCODE_R) PORT_CHANGED_MEMBER(DEVICE_SELF, beta_state, trigger_reset, 0)
INPUT_PORTS_END

/* M6532 Interface */

TIMER_CALLBACK_MEMBER(beta_state::led_refresh)
{
	if (m_ls145_p < 6)
		m_digits[m_ls145_p] = m_segment;
}

uint8_t beta_state::riot_pa_r()
{
	/*

	    bit     description

	    PA0     2716 D0, segment D, key bit 0
	    PA1     2716 D1, segment E, key bit 1
	    PA2     2716 D2, segment C, key bit 2
	    PA3     2716 D3, segment G, key bit 3
	    PA4     2716 D4, segment F, key bit 4
	    PA5     2716 D5, segment B
	    PA6     2716 D6, segment A
	    PA7     2716 D7

	*/

	uint8_t data = 0xff;

	switch (m_ls145_p)
	{
	case 6:
	case 7:
	case 8:
	case 9:
		data &= m_q[m_ls145_p - 6]->read();
		break;
	default:
		if (!m_eprom_oe && !m_eprom_ce)
		{
			data = m_eprom_rom[m_eprom_addr & 0x7ff];
			popmessage("EPROM read %04x = %02x\n", m_eprom_addr & 0x7ff, data);
		}
	}

	return data;
}

void beta_state::riot_pa_w(uint8_t data)
{
	/*

	    bit     description

	    PA0     2716 D0, segment D, key bit 0
	    PA1     2716 D1, segment E, key bit 1
	    PA2     2716 D2, segment C, key bit 2
	    PA3     2716 D3, segment G, key bit 3
	    PA4     2716 D4, segment F, key bit 4
	    PA5     2716 D5, segment B
	    PA6     2716 D6, segment A
	    PA7     2716 D7

	*/

//  logerror("PA %02x\n", data);

	/* display */
	m_segment = bitswap<8>(data, 7, 3, 4, 1, 0, 2, 5, 6) & 0x7f;
	m_led_refresh_timer->adjust(attotime::from_usec(70));

	/* EPROM data */
	m_eprom_data = data;
}

uint8_t beta_state::riot_pb_r()
{
	return 0;
}

void beta_state::riot_pb_w(uint8_t data)
{
	/*

	    bit     description

	    PB0     74LS145 P0
	    PB1     74LS145 P1
	    PB2     74LS145 P2
	    PB3     74LS145 P3, 74LS164 D
	    PB4     loudspeaker, data led
	    PB5     address led, 74LS164 CP
	    PB6     2716 _OE
	    PB7     2716 _CE

	*/

	//logerror("PB %02x %02x\n", data, olddata);

	/* display */
	m_ls145_p = data & 0x0f;

	/* speaker */
	m_speaker->level_w(!BIT(data, 4));

	/* address led */
	m_leds[0] = BIT(data, 5);

	/* data led */
	m_leds[1] = !BIT(data, 5);

	/* EPROM address shift */
	if (!BIT(m_old_data, 5) && BIT(data, 5))
	{
		m_eprom_addr <<= 1;
		m_eprom_addr |= BIT(m_old_data, 3);
	}

	/* EPROM output enable */
	m_eprom_oe = BIT(data, 6);

	/* EPROM chip enable */
	m_eprom_ce = BIT(data, 7);

	if (BIT(data, 6) && (!BIT(m_old_data, 7) && BIT(data, 7)))
	{
		popmessage("EPROM write %04x = %02x\n", m_eprom_addr & 0x7ff, m_eprom_data);
		m_eprom_rom[m_eprom_addr & 0x7ff] &= m_eprom_data;
	}

	m_old_data = data;
}

/* EPROM socket */

DEVICE_IMAGE_LOAD_MEMBER(beta_state::load_beta_eprom)
{
	uint32_t const size = m_eprom->common_get_size("rom");

	if (size != 0x800)
		return std::make_pair(image_error::INVALIDLENGTH, "Unsupported cartridge size (only 2K cartridges are supported)");

	m_eprom->rom_alloc(size, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE);
	m_eprom->common_load_rom(m_eprom->get_rom_base(), size, "rom");

	return std::make_pair(std::error_condition(), std::string());
}

DEVICE_IMAGE_UNLOAD_MEMBER(beta_state::unload_beta_eprom)
{
	if (!image.loaded_through_softlist())
		image.fwrite(&m_eprom_rom[0], 0x800);
}

/* Machine Initialization */

void beta_state::machine_start()
{
	m_digits.resolve();
	m_leds.resolve();

	m_led_refresh_timer = timer_alloc(FUNC(beta_state::led_refresh), this);

	m_eprom_rom.resize(0x800);

	if (!m_eprom->exists())
		memset(&m_eprom_rom[0], 0xff, 0x800);
	else
	{
		std::string region_tag;
		memcpy(&m_eprom_rom[0], memregion(region_tag.assign(m_eprom->tag()).append(GENERIC_ROM_REGION_TAG).c_str())->base(), 0x800);
	}

	// state saving
	save_item(NAME(m_eprom_oe));
	save_item(NAME(m_eprom_ce));
	save_item(NAME(m_eprom_addr));
	save_item(NAME(m_eprom_data));
	save_item(NAME(m_old_data));
	save_item(NAME(m_eprom_rom));
	save_item(NAME(m_ls145_p));
	save_item(NAME(m_segment));
}

/* Machine Driver */

void beta_state::beta(machine_config &config)
{
	/* basic machine hardware */
	M6502(config, m_maincpu, XTAL(4'000'000)/4);
	m_maincpu->set_addrmap(AS_PROGRAM, &beta_state::beta_mem);

	/* video hardware */
	config.set_default_layout(layout_beta);

	/* sound hardware */
	SPEAKER(config, "mono").front_center();
	SPEAKER_SOUND(config, m_speaker).add_route(ALL_OUTPUTS, "mono", 0.25);

	/* devices */
	mos6532_device &m6532(MOS6532(config, M6532_TAG, XTAL(4'000'000)/4));
	m6532.pa_rd_callback().set(FUNC(beta_state::riot_pa_r));
	m6532.pa_wr_callback().set(FUNC(beta_state::riot_pa_w));
	m6532.pb_rd_callback().set(FUNC(beta_state::riot_pb_r));
	m6532.pb_wr_callback().set(FUNC(beta_state::riot_pb_w));
	m6532.irq_wr_callback().set_inputline(m_maincpu, M6502_IRQ_LINE);

	/* EPROM socket */
	generic_cartslot_device &cartslot(GENERIC_CARTSLOT(config, EPROM_TAG, generic_plain_slot, nullptr, "bin,rom"));
	cartslot.set_device_load(FUNC(beta_state::load_beta_eprom));
	cartslot.set_device_unload(FUNC(beta_state::unload_beta_eprom));

	/* internal ram */
	RAM(config, RAM_TAG).set_default_size("256");
}

/* ROMs */

ROM_START( beta )
	ROM_REGION( 0x10000, M6502_TAG, 0 )
	ROM_LOAD( "beta.rom", 0x8000, 0x0800, CRC(d42fdb17) SHA1(595225a0cd43dd76c46b2aff6c0f27d5991cc4f0))
ROM_END

} // anonymous namespace


/* System Drivers */

//    YEAR  NAME  PARENT  COMPAT  MACHINE  INPUT  CLASS       INIT        COMPANY      FULLNAME  FLAGS
COMP( 1984, beta, 0,      0,      beta,    beta,  beta_state, empty_init, "Pitronics", "Beta",   MACHINE_SUPPORTS_SAVE )