apexc.cpp

// license:GPL-2.0+
// copyright-holders:Raphael Nabet, Robbbert
/*
    drivers/apexc.c : APEXC driver

    By Raphael Nabet

    see cpu/apexc.c for background and tech info
*/

#include "emu.h"
#include "cpu/apexc/apexc.h"
#include "screen.h"


class apexc_state : public driver_device
{
public:
	apexc_state(const machine_config &mconfig, device_type type, const char *tag)
		: driver_device(mconfig, type, tag) ,
		m_maincpu(*this, "maincpu"),
		m_gfxdecode(*this, "gfxdecode"),
		m_palette(*this, "palette"),
		m_screen(*this, "screen")  { }

	uint32_t m_panel_data_reg;    /* value of a data register on the control panel which can
	                            be edited - the existence of this register is a personnal
	                            guess */

	std::unique_ptr<bitmap_ind16> m_bitmap;

	uint32_t m_old_edit_keys;
	int m_old_control_keys;

	int m_letters;
	int m_pos;
	DECLARE_DRIVER_INIT(apexc);
	virtual void machine_start() override;
	virtual void video_start() override;
	DECLARE_PALETTE_INIT(apexc);
	uint32_t screen_update_apexc(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
	INTERRUPT_GEN_MEMBER(apexc_interrupt);
	DECLARE_READ8_MEMBER(tape_read);
	DECLARE_WRITE8_MEMBER(tape_write);
	void apexc_draw_led(bitmap_ind16 &bitmap, int x, int y, int state);
	void apexc_draw_char(bitmap_ind16 &bitmap, char character, int x, int y, int color);
	void apexc_draw_string(bitmap_ind16 &bitmap, const char *buf, int x, int y, int color);
	void apexc_teletyper_init();
	void apexc_teletyper_linefeed();
	void apexc_teletyper_putchar(int character);
	required_device<cpu_device> m_maincpu;
	required_device<gfxdecode_device> m_gfxdecode;
	required_device<palette_device> m_palette;
	required_device<screen_device> m_screen;
};

void apexc_state::machine_start()
{
	apexc_teletyper_init();
}


/*
    APEXC RAM loading/saving from cylinder image

    Note that, in an actual APEXC, the RAM contents are not read from the cylinder :
    the cylinder IS the RAM.

    This feature is important : of course, the tape reader allows to enter programs, but you
    still need an object code loader in memory.  (Of course, the control panel enables
    the user to enter such a loader manually, but it would take hours...)
*/

class apexc_cylinder_image_device : public device_t, public device_image_interface
{
public:
	// construction/destruction
	apexc_cylinder_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	// image-level overrides
	virtual iodevice_t image_type() const override { return IO_CYLINDER; }

	virtual bool is_readable()  const override { return 1; }
	virtual bool is_writeable() const override { return 1; }
	virtual bool is_creatable() const override { return 0; }
	virtual bool must_be_loaded() const override { return 0; }
	virtual bool is_reset_on_load() const override { return 1; }
	virtual const char *file_extensions() const override { return "apc"; }

	virtual image_init_result call_load() override;
	virtual void call_unload() override;
protected:
	// device-level overrides
	virtual void device_start() override { }
private:
	int m_writable;
};

DEFINE_DEVICE_TYPE(APEXC_CYLINDER, apexc_cylinder_image_device, "apexc_cylinder_image", "APEXC Cylinder")

apexc_cylinder_image_device::apexc_cylinder_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
	: device_t(mconfig, APEXC_CYLINDER, tag, owner, clock)
	, device_image_interface(mconfig, *this)
{
}

/*
    Open cylinder image and read RAM
*/
image_init_result apexc_cylinder_image_device::call_load()
{
	/* load RAM contents */
	m_writable = !is_readonly();

	fread( machine().root_device().memregion("maincpu")->base(), 0x1000);
#ifdef LSB_FIRST
	{   /* fix endianness */
		uint32_t *RAM = (uint32_t *)(machine().root_device().memregion("maincpu")->base());

		for (int i=0; i < 0x0400; i++)
			RAM[i] = big_endianize_int32(RAM[i]);
	}
#endif

	return image_init_result::PASS;
}

/*
    Save RAM to cylinder image and close it
*/
void apexc_cylinder_image_device::call_unload()
{
	if (m_writable)
	{   /* save RAM contents */
		/* rewind file */
		fseek(0, SEEK_SET);
#ifdef LSB_FIRST
		{   /* fix endianness */
			uint32_t *RAM = (uint32_t *)(machine().root_device().memregion("maincpu")->base());

			for (int i=0; i < /*0x2000*/0x0400; i++)
				RAM[i] = big_endianize_int32(RAM[i]);
		}
#endif
		/* write */
		fwrite(machine().root_device().memregion("maincpu")->base(), /*0x8000*/0x1000);
	}
}


#define MCFG_APEXC_CYLINDER_ADD(_tag) \
	MCFG_DEVICE_ADD(_tag, APEXC_CYLINDER, 0)


/*
    APEXC tape support

    APEXC does all I/O on paper tape.  There are 5 punch rows on tape.

    Both a reader (read-only), and a puncher (write-only) are provided.

    Tape output can be fed into a teletyper, in order to have text output :

    code                    Symbol
    (binary)        Letters         Figures
    00000                           0
    00001           T               1
    00010           B               2
    00011           O               3
    00100           E               4
    00101           H               5
    00110           N               6
    00111           M               7
    01000           A               8
    01001           L               9
    01010           R               +
    01011           G               -
    01100           I               z
    01101           P               .
    01110           C               d
    01111           V               =
    10000                   Space
    10001           Z               y
    10010           D               theta (greek letter)
    10011                   Line Space (i.e. LF)
    10100           S               ,
    10101           Y               Sigma (greek letter)
    10110           F               x
    10111           X               /
    11000                   Carriage Return
    11001           W               phi (greek letter)
    11010           J               - (dash ?)
    11011                   Figures
    11100           U               pi (greek letter)
    11101           Q               )
    11110           K               (
    11111                   Letters
*/

class apexc_tape_puncher_image_device : public device_t, public device_image_interface
{
public:
	// construction/destruction
	apexc_tape_puncher_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	// image-level overrides
	virtual iodevice_t image_type() const override { return IO_PUNCHTAPE; }

	virtual bool is_readable()  const override { return 0; }
	virtual bool is_writeable() const override { return 1; }
	virtual bool is_creatable() const override { return 1; }
	virtual bool must_be_loaded() const override { return 0; }
	virtual bool is_reset_on_load() const override { return 0; }
	virtual const char *file_extensions() const override { return "tap"; }
protected:
	// device-level overrides
	virtual void device_start() override { }
};

DEFINE_DEVICE_TYPE(APEXC_TAPE_PUNCHER, apexc_tape_puncher_image_device, "apexc_tape_puncher_image", "APEXC Tape Puncher")

apexc_tape_puncher_image_device::apexc_tape_puncher_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
	: device_t(mconfig, APEXC_TAPE_PUNCHER, tag, owner, clock)
	, device_image_interface(mconfig, *this)
{
}

#define MCFG_APEXC_TAPE_PUNCHER_ADD(_tag) \
	MCFG_DEVICE_ADD(_tag, APEXC_TAPE_PUNCHER, 0)

class apexc_tape_reader_image_device :  public device_t, public device_image_interface
{
public:
	// construction/destruction
	apexc_tape_reader_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	// image-level overrides
	virtual iodevice_t image_type() const override { return IO_PUNCHTAPE; }

	virtual bool is_readable()  const override { return 1; }
	virtual bool is_writeable() const override { return 0; }
	virtual bool is_creatable() const override { return 0; }
	virtual bool must_be_loaded() const override { return 0; }
	virtual bool is_reset_on_load() const override { return 0; }
	virtual const char *file_extensions() const override { return "tap"; }
protected:
	// device-level overrides
	virtual void device_start() override { }
};

DEFINE_DEVICE_TYPE(APEXC_TAPE_READER, apexc_tape_reader_image_device, "apexc_tape_reader_image", "APEXC Tape Reader")

apexc_tape_reader_image_device::apexc_tape_reader_image_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
	: device_t(mconfig, APEXC_TAPE_READER, tag, owner, clock)
	, device_image_interface(mconfig, *this)
{
}

#define MCFG_APEXC_TAPE_READER_ADD(_tag) \
	MCFG_DEVICE_ADD(_tag, APEXC_TAPE_READER, 0)

/*
    Open a tape image
*/

READ8_MEMBER(apexc_state::tape_read)
{
	device_t *device = machine().device("tape_reader");
	uint8_t reply;
	device_image_interface *image = dynamic_cast<device_image_interface *>(device);

	if (image->exists() && (image->fread(& reply, 1) == 1))
		return reply & 0x1f;
	else
		return 0;   /* unit not ready - I don't know what we should do */
}

WRITE8_MEMBER(apexc_state::tape_write)
{
	device_t *device = machine().device("tape_puncher");
	uint8_t data5 = (data & 0x1f);
	device_image_interface *image = dynamic_cast<device_image_interface *>(device);

	if (image->exists())
		image->fwrite(& data5, 1);

	apexc_teletyper_putchar(data & 0x1f);    /* display on screen */
}

/*
    APEXC control panel

    I know really little about the details, although the big picture is obvious.

    Things I know :
    * "As well as starting and stopping the machine, [it] enables information to be inserted
    manually and provides for the inspection of the contents of the memory via various
    storage registers." (Booth, p. 2)
    * "Data can be inserted manually from the control panel [into the control register]".
    (Booth, p. 3)
    * The contents of the R register can be edited, too.  A button allows to clear
    a complete X (or Y ???) field.  (forgot the reference, but must be somewhere in Booth)
    * There is no trace mode (Booth, p. 213)

    Since the control panel is necessary for the operation of the APEXC, I tried to
    implement a commonplace control panel.  I cannot tell how close the feature set and
    operation of this control panel is to the original APEXC control panel, but it
    cannot be too different in the basic principles.
*/


#if 0
/* defines for input port numbers */
enum
{
	panel_control = 0,
	panel_edit1,
	panel_edit2
};
#endif


/* defines for each bit and mask in input port panel_control */
enum
{
	/* bit numbers */
	panel_run_bit = 0,
	panel_CR_bit,
	panel_A_bit,
	panel_R_bit,
	panel_HB_bit,
	panel_ML_bit,
	panel_mem_bit,
	panel_write_bit,

	/* masks */
	panel_run = (1 << panel_run_bit),
	panel_CR  = (1 << panel_CR_bit),
	panel_A   = (1 << panel_A_bit),
	panel_R   = (1 << panel_R_bit),
	panel_HB  = (1 << panel_HB_bit),
	panel_ML  = (1 << panel_ML_bit),
	panel_mem = (1 << panel_mem_bit),
	panel_write = (1 << panel_write_bit)
};

/* fake input ports with keyboard keys */
static INPUT_PORTS_START(apexc)

	PORT_START("panel") /* 0 : panel control */
	PORT_BIT(panel_run, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Run/Stop")                PORT_CODE(KEYCODE_ENTER)
	PORT_BIT(panel_CR,  IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read CR")                 PORT_CODE(KEYCODE_1_PAD)
	PORT_BIT(panel_A,   IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read A")                  PORT_CODE(KEYCODE_2_PAD)
	PORT_BIT(panel_R,   IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read R")                  PORT_CODE(KEYCODE_3_PAD)
	PORT_BIT(panel_HB,  IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read HB")                 PORT_CODE(KEYCODE_4_PAD)
	PORT_BIT(panel_ML,  IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read ML")                 PORT_CODE(KEYCODE_5_PAD)
	PORT_BIT(panel_mem, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Read mem")                PORT_CODE(KEYCODE_6_PAD)
	PORT_BIT(panel_write, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Write instead of read") PORT_CODE(KEYCODE_LSHIFT)

	PORT_START("data")  /* data edit */
	PORT_BIT(0x80000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #1")              PORT_CODE(KEYCODE_1)
	PORT_BIT(0x40000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #2")              PORT_CODE(KEYCODE_2)
	PORT_BIT(0x20000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #3")              PORT_CODE(KEYCODE_3)
	PORT_BIT(0x10000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #4")              PORT_CODE(KEYCODE_4)
	PORT_BIT(0x08000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #5")              PORT_CODE(KEYCODE_5)
	PORT_BIT(0x04000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #6")              PORT_CODE(KEYCODE_6)
	PORT_BIT(0x02000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #7")              PORT_CODE(KEYCODE_7)
	PORT_BIT(0x01000000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #8")              PORT_CODE(KEYCODE_8)
	PORT_BIT(0x00800000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #9")              PORT_CODE(KEYCODE_9)
	PORT_BIT(0x00400000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #10")             PORT_CODE(KEYCODE_0)
	PORT_BIT(0x00200000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #11")             PORT_CODE(KEYCODE_Q)
	PORT_BIT(0x00100000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #12")             PORT_CODE(KEYCODE_W)
	PORT_BIT(0x00080000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #13")             PORT_CODE(KEYCODE_E)
	PORT_BIT(0x00040000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #14")             PORT_CODE(KEYCODE_R)
	PORT_BIT(0x00020000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #15")             PORT_CODE(KEYCODE_T)
	PORT_BIT(0x00010000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #16")             PORT_CODE(KEYCODE_Y)

	PORT_BIT(0x00008000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #17")             PORT_CODE(KEYCODE_U)
	PORT_BIT(0x00004000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #18")             PORT_CODE(KEYCODE_I)
	PORT_BIT(0x00002000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #19")             PORT_CODE(KEYCODE_O)
	PORT_BIT(0x00001000, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #20")             PORT_CODE(KEYCODE_OPENBRACE)
	PORT_BIT(0x00000800, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #21")             PORT_CODE(KEYCODE_A)
	PORT_BIT(0x00000400, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #22")             PORT_CODE(KEYCODE_S)
	PORT_BIT(0x00000200, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #23")             PORT_CODE(KEYCODE_D)
	PORT_BIT(0x00000100, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #24")             PORT_CODE(KEYCODE_F)
	PORT_BIT(0x00000080, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #25")             PORT_CODE(KEYCODE_G)
	PORT_BIT(0x00000040, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #26")             PORT_CODE(KEYCODE_H)
	PORT_BIT(0x00000020, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #27")             PORT_CODE(KEYCODE_J)
	PORT_BIT(0x00000010, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #28")             PORT_CODE(KEYCODE_K)
	PORT_BIT(0x00000008, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #29")             PORT_CODE(KEYCODE_L)
	PORT_BIT(0x00000004, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #30")             PORT_CODE(KEYCODE_Z)
	PORT_BIT(0x00000002, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #31")             PORT_CODE(KEYCODE_X)
	PORT_BIT(0x00000001, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Toggle bit #32")             PORT_CODE(KEYCODE_C)
INPUT_PORTS_END


/*
    Not a real interrupt - just handle keyboard input
*/
INTERRUPT_GEN_MEMBER(apexc_state::apexc_interrupt)
{
	address_space& space = m_maincpu->space(AS_PROGRAM);
	uint32_t edit_keys;
	int control_keys;

	int control_transitions;


	/* read new state of edit keys */
	edit_keys = ioport("data")->read();

	/* toggle data reg according to transitions */
	m_panel_data_reg ^= edit_keys & (~m_old_edit_keys);

	/* remember new state of edit keys */
	m_old_edit_keys = edit_keys;


	/* read new state of control keys */
	control_keys = ioport("panel")->read();

	/* compute transitions */
	control_transitions = control_keys & (~m_old_control_keys);

	/* process commands */

	if (control_transitions & panel_run)
	{   /* toggle run/stop state */
		m_maincpu->set_state_int(APEXC_STATE, ! m_maincpu->state_int(APEXC_STATE));
	}

	while (control_transitions & (panel_CR | panel_A | panel_R | panel_ML | panel_HB))
	{   /* read/write a register */
		/* note that we must take into account the possibility of simulteanous keypresses
		(which would be a goofy thing to do when reading, but a normal one when writing,
		if the user wants to clear several registers at once) */
		int reg_id = -1;

		/* determinate value of reg_id */
		if (control_transitions & panel_CR)
		{   /* CR register selected ? */
			control_transitions &= ~panel_CR;   /* clear so that it is ignored on next iteration */
			reg_id = APEXC_CR;          /* matching register ID */
		}
		else if (control_transitions & panel_A)
		{
			control_transitions &= ~panel_A;
			reg_id = APEXC_A;
		}
		else if (control_transitions & panel_R)
		{
			control_transitions &= ~panel_R;
			reg_id = APEXC_R;
		}
		else if (control_transitions & panel_HB)
		{
			control_transitions &= ~panel_HB;
			reg_id = APEXC_WS;
		}
		else if (control_transitions & panel_ML)
		{
			control_transitions &= ~panel_ML;
			reg_id = APEXC_ML;
		}

		if (-1 != reg_id)
		{
			/* read/write register #reg_id */
			if (control_keys & panel_write)
				/* write reg */
				m_maincpu->set_state_int(reg_id, m_panel_data_reg);
			else
				/* read reg */
				m_panel_data_reg = m_maincpu->state_int(reg_id);
		}
	}

	if (control_transitions & panel_mem)
	{   /* read/write memory */

		if (control_keys & panel_write) {
			/* write memory */
			space.write_dword(m_maincpu->pc(), m_panel_data_reg);
		}
		else {
			/* read memory */
			m_panel_data_reg = space.read_dword(m_maincpu->pc());
		}
	}

	/* remember new state of control keys */
	m_old_control_keys = control_keys;
}

/*
    apexc video emulation.

    Since the APEXC has no video display, we display the control panel.

    Additionally, We display one page of teletyper output.
*/

static const rgb_t apexc_palette[] =
{
	rgb_t::white(),
	rgb_t::black(),
	rgb_t(255, 0, 0),
	rgb_t(50, 0, 0)
};

#if 0
static const unsigned short apexc_colortable[] =
{
	0, 1
};
#endif

#define APEXC_PALETTE_SIZE ARRAY_LENGTH(apexc_palette)
#define APEXC_COLORTABLE_SIZE sizeof(apexc_colortable)/2

enum
{
	/* size and position of panel window */
	panel_window_width = 256,
	panel_window_height = 64,
	panel_window_offset_x = 0,
	panel_window_offset_y = 0,
	/* size and position of teletyper window */
	teletyper_window_width = 256,
	teletyper_window_height = 128,
	teletyper_window_offset_x = 0,
	teletyper_window_offset_y = panel_window_height
};

static const rectangle panel_window(
	panel_window_offset_x,  panel_window_offset_x+panel_window_width-1, /* min_x, max_x */
	panel_window_offset_y,  panel_window_offset_y+panel_window_height-1/* min_y, max_y */
);
static const rectangle teletyper_window(
	teletyper_window_offset_x,  teletyper_window_offset_x+teletyper_window_width-1, /* min_x, max_x */
	teletyper_window_offset_y,  teletyper_window_offset_y+teletyper_window_height-1/* min_y, max_y */
);
enum
{
	teletyper_scroll_step = 8
};
static const rectangle teletyper_scroll_clear_window(
	teletyper_window_offset_x,  teletyper_window_offset_x+teletyper_window_width-1, /* min_x, max_x */
	teletyper_window_offset_y+teletyper_window_height-teletyper_scroll_step,    teletyper_window_offset_y+teletyper_window_height-1 /* min_y, max_y */
);
//static const int var_teletyper_scroll_step = - teletyper_scroll_step;

PALETTE_INIT_MEMBER(apexc_state, apexc)
{
	palette.set_pen_colors(0, apexc_palette, APEXC_PALETTE_SIZE);
}

void apexc_state::video_start()
{
	int width = m_screen->width();
	int height = m_screen->height();

	m_bitmap = std::make_unique<bitmap_ind16>(width, height);
	m_bitmap->fill(0, /*machine().visible_area*/teletyper_window);
}

/* draw a small 8*8 LED (well, there were no LEDs at the time, so let's call this a lamp ;-) ) */
void apexc_state::apexc_draw_led(bitmap_ind16 &bitmap, int x, int y, int state)
{
	int xx, yy;

	for (yy=1; yy<7; yy++)
		for (xx=1; xx<7; xx++)
			bitmap.pix16(y+yy, x+xx) = state ? 2 : 3;
}

/* write a single char on screen */
void apexc_state::apexc_draw_char(bitmap_ind16 &bitmap, char character, int x, int y, int color)
{
	m_gfxdecode->gfx(0)->transpen(bitmap,bitmap.cliprect(), character-32, color, 0, 0,
				x+1, y, 0);
}

/* write a string on screen */
void apexc_state::apexc_draw_string(bitmap_ind16 &bitmap, const char *buf, int x, int y, int color)
{
	while (* buf)
	{
		apexc_draw_char(bitmap, *buf, x, y, color);

		x += 8;
		buf++;
	}
}


uint32_t apexc_state::screen_update_apexc(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	int i;
	char the_char;

	bitmap.fill(0, /*machine().visible_area*/panel_window);
	apexc_draw_string(bitmap, "power", 8, 0, 0);
	apexc_draw_string(bitmap, "running", 8, 8, 0);
	apexc_draw_string(bitmap, "data :", 0, 24, 0);

	copybitmap(bitmap, *m_bitmap, 0, 0, 0, 0, teletyper_window);


	apexc_draw_led(bitmap, 0, 0, 1);

	apexc_draw_led(bitmap, 0, 8, m_maincpu->state_int(APEXC_STATE));

	for (i=0; i<32; i++)
	{
		apexc_draw_led(bitmap, i*8, 32, (m_panel_data_reg << i) & 0x80000000UL);
		the_char = '0' + ((i + 1) % 10);
		apexc_draw_char(bitmap, the_char, i*8, 40, 0);
		if (((i + 1) % 10) == 0)
		{
			the_char = '0' + ((i + 1) / 10);
			apexc_draw_char(bitmap, the_char, i*8, 48, 0);
		}
	}
	return 0;
}

void apexc_state::apexc_teletyper_init()
{
	m_letters = false;
	m_pos = 0;
}

void apexc_state::apexc_teletyper_linefeed()
{
	uint8_t buf[teletyper_window_width];
	int y;

	for (y=teletyper_window_offset_y; y<teletyper_window_offset_y+teletyper_window_height-teletyper_scroll_step; y++)
	{
		extract_scanline8(*m_bitmap, teletyper_window_offset_x, y+teletyper_scroll_step, teletyper_window_width, buf);
		draw_scanline8(*m_bitmap, teletyper_window_offset_x, y, teletyper_window_width, buf, m_palette->pens());
	}

	m_bitmap->fill(0, teletyper_scroll_clear_window);
}

void apexc_state::apexc_teletyper_putchar(int character)
{
	static const char ascii_table[2][32] =
	{
		{
			'0',                '1',                '2',                '3',
			'4',                '5',                '6',                '7',
			'8',                '9',                '+',                '-',
			'z',                '.',                'd',                '=',
			' ',                'y',                /*'@'*/'\200'/*theta*/,'\n'/*Line Space*/,
			',',                /*'&'*/'\201'/*Sigma*/,'x',             '/',
			'\r'/*Carriage Return*/,/*'!'*/'\202'/*Phi*/,'_'/*???*/,    '\0'/*Figures*/,
			/*'#'*/'\203'/*pi*/,')',                '(',                '\0'/*Letters*/
		},
		{
			' '/*???*/,         'T',                'B',                'O',
			'E',                'H',                'N',                'M',
			'A',                'L',                'R',                'G',
			'I',                'P',                'C',                'V',
			' ',                'Z',                'D',                '\n'/*Line Space*/,
			'S',                'Y',                'F',                'X',
			'\r'/*Carriage Return*/,'W',            'J',                '\0'/*Figures*/,
			'U',                'Q',                'K',                '\0'/*Letters*/
		}
	};

	char buffer[2] = "x";

	character &= 0x1f;

	switch (character)
	{
	case 19:
		/* Line Space */
		apexc_teletyper_linefeed();
		break;

	case 24:
		/* Carriage Return */
		m_pos = 0;
		break;

	case 27:
		/* Figures */
		m_letters = false;
		break;

	case 31:
		/* Letters */
		m_letters = true;
		break;

	default:
		/* Any printable character... */

		if (m_pos >= 32)
		{   /* if past right border, wrap around */
			apexc_teletyper_linefeed();  /* next line */
			m_pos = 0;                   /* return to start of line */
		}

		/* print character */
		buffer[0] = ascii_table[m_letters][character];   /* lookup ASCII equivalent in table */
		buffer[1] = '\0';                               /* terminate string */
		apexc_draw_string(*m_bitmap, buffer, 8*m_pos, 176, 0);   /* print char */
		m_pos++;                                         /* step carriage forward */

		break;
	}
}

enum
{
	apexc_charnum = /*96+4*/128,    /* ASCII set + 4 special characters */
									/* for whatever reason, 96+4 breaks greek characters */

	apexcfontdata_size = 8 * apexc_charnum
};

/* apexc driver init : builds a font for use by the teletyper */
DRIVER_INIT_MEMBER(apexc_state,apexc)
{
	uint8_t *dst;

	static const unsigned char fontdata6x8[apexcfontdata_size] =
	{   /* ASCII characters */
		0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x20,0x20,0x20,0x00,0x20,0x00,
		0x50,0x50,0x50,0x00,0x00,0x00,0x00,0x00,0x00,0x50,0xf8,0x50,0xf8,0x50,0x00,0x00,
		0x20,0x70,0xc0,0x70,0x18,0xf0,0x20,0x00,0x40,0xa4,0x48,0x10,0x20,0x48,0x94,0x08,
		0x60,0x90,0xa0,0x40,0xa8,0x90,0x68,0x00,0x10,0x20,0x40,0x00,0x00,0x00,0x00,0x00,
		0x20,0x40,0x40,0x40,0x40,0x40,0x20,0x00,0x10,0x08,0x08,0x08,0x08,0x08,0x10,0x00,
		0x20,0xa8,0x70,0xf8,0x70,0xa8,0x20,0x00,0x00,0x20,0x20,0xf8,0x20,0x20,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x60,0x00,0x00,0x00,0xf8,0x00,0x00,0x00,0x00,
		0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x08,0x10,0x20,0x40,0x80,0x00,0x00,
		0x70,0x88,0x88,0x88,0x88,0x88,0x70,0x00,0x10,0x30,0x10,0x10,0x10,0x10,0x10,0x00,
		0x70,0x88,0x08,0x10,0x20,0x40,0xf8,0x00,0x70,0x88,0x08,0x30,0x08,0x88,0x70,0x00,
		0x10,0x30,0x50,0x90,0xf8,0x10,0x10,0x00,0xf8,0x80,0xf0,0x08,0x08,0x88,0x70,0x00,
		0x70,0x80,0xf0,0x88,0x88,0x88,0x70,0x00,0xf8,0x08,0x08,0x10,0x20,0x20,0x20,0x00,
		0x70,0x88,0x88,0x70,0x88,0x88,0x70,0x00,0x70,0x88,0x88,0x88,0x78,0x08,0x70,0x00,
		0x00,0x00,0x30,0x30,0x00,0x30,0x30,0x00,0x00,0x00,0x30,0x30,0x00,0x30,0x30,0x60,
		0x10,0x20,0x40,0x80,0x40,0x20,0x10,0x00,0x00,0x00,0xf8,0x00,0xf8,0x00,0x00,0x00,
		0x40,0x20,0x10,0x08,0x10,0x20,0x40,0x00,0x70,0x88,0x08,0x10,0x20,0x00,0x20,0x00,
		0x70,0x88,0xb8,0xa8,0xb8,0x80,0x70,0x00,0x70,0x88,0x88,0xf8,0x88,0x88,0x88,0x00,
		0xf0,0x88,0x88,0xf0,0x88,0x88,0xf0,0x00,0x70,0x88,0x80,0x80,0x80,0x88,0x70,0x00,
		0xf0,0x88,0x88,0x88,0x88,0x88,0xf0,0x00,0xf8,0x80,0x80,0xf0,0x80,0x80,0xf8,0x00,
		0xf8,0x80,0x80,0xf0,0x80,0x80,0x80,0x00,0x70,0x88,0x80,0x98,0x88,0x88,0x70,0x00,
		0x88,0x88,0x88,0xf8,0x88,0x88,0x88,0x00,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x00,
		0x08,0x08,0x08,0x08,0x88,0x88,0x70,0x00,0x88,0x90,0xa0,0xc0,0xa0,0x90,0x88,0x00,
		0x80,0x80,0x80,0x80,0x80,0x80,0xf8,0x00,0x88,0xd8,0xa8,0x88,0x88,0x88,0x88,0x00,
		0x88,0xc8,0xa8,0x98,0x88,0x88,0x88,0x00,0x70,0x88,0x88,0x88,0x88,0x88,0x70,0x00,
		0xf0,0x88,0x88,0xf0,0x80,0x80,0x80,0x00,0x70,0x88,0x88,0x88,0x88,0x88,0x70,0x08,
		0xf0,0x88,0x88,0xf0,0x88,0x88,0x88,0x00,0x70,0x88,0x80,0x70,0x08,0x88,0x70,0x00,
		0xf8,0x20,0x20,0x20,0x20,0x20,0x20,0x00,0x88,0x88,0x88,0x88,0x88,0x88,0x70,0x00,
		0x88,0x88,0x88,0x88,0x88,0x50,0x20,0x00,0x88,0x88,0x88,0x88,0xa8,0xd8,0x88,0x00,
		0x88,0x50,0x20,0x20,0x20,0x50,0x88,0x00,0x88,0x88,0x88,0x50,0x20,0x20,0x20,0x00,
		0xf8,0x08,0x10,0x20,0x40,0x80,0xf8,0x00,0x30,0x20,0x20,0x20,0x20,0x20,0x30,0x00,
		0x40,0x40,0x20,0x20,0x10,0x10,0x08,0x08,0x30,0x10,0x10,0x10,0x10,0x10,0x30,0x00,
		0x20,0x50,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xfc,
		0x40,0x20,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x70,0x08,0x78,0x88,0x78,0x00,
		0x80,0x80,0xf0,0x88,0x88,0x88,0xf0,0x00,0x00,0x00,0x70,0x88,0x80,0x80,0x78,0x00,
		0x08,0x08,0x78,0x88,0x88,0x88,0x78,0x00,0x00,0x00,0x70,0x88,0xf8,0x80,0x78,0x00,
		0x18,0x20,0x70,0x20,0x20,0x20,0x20,0x00,0x00,0x00,0x78,0x88,0x88,0x78,0x08,0x70,
		0x80,0x80,0xf0,0x88,0x88,0x88,0x88,0x00,0x20,0x00,0x20,0x20,0x20,0x20,0x20,0x00,
		0x20,0x00,0x20,0x20,0x20,0x20,0x20,0xc0,0x80,0x80,0x90,0xa0,0xe0,0x90,0x88,0x00,
		0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x00,0x00,0x00,0xf0,0xa8,0xa8,0xa8,0xa8,0x00,
		0x00,0x00,0xb0,0xc8,0x88,0x88,0x88,0x00,0x00,0x00,0x70,0x88,0x88,0x88,0x70,0x00,
		0x00,0x00,0xf0,0x88,0x88,0xf0,0x80,0x80,0x00,0x00,0x78,0x88,0x88,0x78,0x08,0x08,
		0x00,0x00,0xb0,0xc8,0x80,0x80,0x80,0x00,0x00,0x00,0x78,0x80,0x70,0x08,0xf0,0x00,
		0x20,0x20,0x70,0x20,0x20,0x20,0x18,0x00,0x00,0x00,0x88,0x88,0x88,0x98,0x68,0x00,
		0x00,0x00,0x88,0x88,0x88,0x50,0x20,0x00,0x00,0x00,0xa8,0xa8,0xa8,0xa8,0x50,0x00,
		0x00,0x00,0x88,0x50,0x20,0x50,0x88,0x00,0x00,0x00,0x88,0x88,0x88,0x78,0x08,0x70,
		0x00,0x00,0xf8,0x10,0x20,0x40,0xf8,0x00,0x08,0x10,0x10,0x20,0x10,0x10,0x08,0x00,
		0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x40,0x20,0x20,0x10,0x20,0x20,0x40,0x00,
		0x00,0x68,0xb0,0x00,0x00,0x00,0x00,0x00,0x20,0x50,0x20,0x50,0xa8,0x50,0x00,0x00,

		/* theta */
		0x70,
		0x88,
		0x88,
		0xF8,
		0x88,
		0x88,
		0x70,
		0x00,

		/* Sigma */
		0xf8,
		0x40,
		0x20,
		0x10,
		0x20,
		0x40,
		0xf8,
		0x00,

		/* Phi */
		0x20,
		0x70,
		0xA8,
		0xA8,
		0xA8,
		0xA8,
		0x70,
		0x20,

		/* pi */
		0x00,
		0x00,
		0xF8,
		0x50,
		0x50,
		0x50,
		0x50,
		0x00
	};

	dst = memregion("chargen")->base();

	memcpy(dst, fontdata6x8, apexcfontdata_size);
}

static const gfx_layout fontlayout =
{
	6, 8,           /* 6*8 characters */
	apexc_charnum,  /* 96+4 characters */
	1,              /* 1 bit per pixel */
	{ 0 },
	{ 0, 1, 2, 3, 4, 5, 6, 7 }, /* straightforward layout */
	{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
	8*8 /* every char takes 8 consecutive bytes */
};

static GFXDECODE_START( apexc )
	GFXDECODE_ENTRY( "chargen", 0, fontlayout, 0, 2 )
GFXDECODE_END


static ADDRESS_MAP_START(apexc_mem_map, AS_PROGRAM, 32, apexc_state )
#if 0
	AM_RANGE(0x0000, 0x03ff) AM_RAM /* 1024 32-bit words (expandable to 8192) */
	AM_RANGE(0x0400, 0x1fff) AM_NOP
#else
	AM_RANGE(0x0000, 0x0fff) AM_RAM AM_REGION("maincpu", 0x0000)
	AM_RANGE(0x1000, 0x7fff) AM_NOP
#endif
ADDRESS_MAP_END


static MACHINE_CONFIG_START( apexc )

	/* basic machine hardware */
	/* APEXC CPU @ 2.0 kHz (memory word clock frequency) */
	MCFG_CPU_ADD("maincpu", APEXC, 2000)
	MCFG_CPU_PROGRAM_MAP(apexc_mem_map)
	MCFG_APEXC_TAPE_READ_CB(READ8(apexc_state, tape_read))
	MCFG_APEXC_TAPE_PUNCH_CB(WRITE8(apexc_state, tape_write))
	/* dummy interrupt: handles the control panel */
	MCFG_CPU_VBLANK_INT_DRIVER("screen", apexc_state,  apexc_interrupt)


	/* video hardware does not exist, but we display a control panel and the typewriter output */
	MCFG_SCREEN_ADD("screen", RASTER)
	MCFG_SCREEN_REFRESH_RATE(60)
	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
	MCFG_SCREEN_SIZE(256, 192)
	MCFG_SCREEN_VISIBLE_AREA(0, 256-1, 0, 192-1)
	MCFG_SCREEN_UPDATE_DRIVER(apexc_state, screen_update_apexc)
	MCFG_SCREEN_PALETTE("palette")

	MCFG_GFXDECODE_ADD("gfxdecode", "palette", apexc)
	MCFG_PALETTE_ADD("palette", APEXC_PALETTE_SIZE)
	MCFG_PALETTE_INIT_OWNER(apexc_state, apexc)


	MCFG_APEXC_CYLINDER_ADD("cylinder")
	MCFG_APEXC_TAPE_PUNCHER_ADD("tape_puncher")
	MCFG_APEXC_TAPE_READER_ADD("tape_reader")
MACHINE_CONFIG_END

ROM_START(apexc)
	/*CPU memory space*/
	ROM_REGION32_BE(0x10000, "maincpu", ROMREGION_ERASEFF)
		/* Note this computer has no ROM... */

	ROM_REGION(apexcfontdata_size, "chargen", ROMREGION_ERASEFF)
		/* space filled with our font */
ROM_END

//     YEAR     NAME        PARENT    COMPAT  MACHINE     INPUT  STATE         INIT   COMPANY                FULLNAME */
//COMP(  1951,    apexc53,    0,        0,      apexc53,    apexc, apexc_state,  apexc, "Andrew Donald Booth", "All Purpose Electronic X-ray Computer (as described in 1953)" , MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW)
COMP(  1955,    apexc,      0,        0,      apexc,      apexc, apexc_state,  apexc, "Andrew Donald Booth", "All Purpose Electronic X-ray Computer (as described in 1957)" , MACHINE_NO_SOUND_HW)