// license:BSD-3-Clause
// copyright-holders:Miodrag Milanovic, Robbbert
/**********************************************************************************

    General Processor Modello T

    2012-12-10 Skeleton driver.
    2013-09-27 Added keyboard and cursor.

    Made in Italy, a single board with numerous small daughter boards.
    The 3 units (keyboard, disk drives, main unit) had wooden cabinets.
    It had an inbuilt small green-screen CRT, like a Kaypro, and the RAM could
    be 16, 32, or 48k. The FDC is a FD1791.

    All the articles and doco (what there is of it) is all in Italian.

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

#include "emu.h"
#include "cpu/z80/z80.h"
#include "machine/keyboard.h"

#define KEYBOARD_TAG "keyboard"

class modellot_state : public driver_device
{
public:
	modellot_state(const machine_config &mconfig, device_type type, const char *tag)
		: driver_device(mconfig, type, tag),
		m_p_videoram(*this, "videoram"),
		m_maincpu(*this, "maincpu")
	{
	}

	DECLARE_READ8_MEMBER(port77_r);
	DECLARE_READ8_MEMBER(portff_r);
	DECLARE_WRITE8_MEMBER(kbd_put);
	UINT32 screen_update_modellot(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
	required_shared_ptr<UINT8> m_p_videoram;
private:
	UINT8 m_term_data;
	const UINT8 *m_p_chargen;
	virtual void machine_reset() override;
	required_device<cpu_device> m_maincpu;
};

static ADDRESS_MAP_START(modellot_mem, AS_PROGRAM, 8, modellot_state)
	ADDRESS_MAP_UNMAP_HIGH
	AM_RANGE(0x0000, 0xbfff) AM_RAM // 48k ram
	AM_RANGE(0xc000, 0xc3ff) AM_RAM AM_SHARE("videoram")
	AM_RANGE(0xe000, 0xffff) AM_ROM
ADDRESS_MAP_END

static ADDRESS_MAP_START(modellot_io, AS_IO, 8, modellot_state)
	ADDRESS_MAP_UNMAP_HIGH
	ADDRESS_MAP_GLOBAL_MASK(0xff)
	AM_RANGE(0x77, 0x77) AM_READ(port77_r)
	AM_RANGE(0xff, 0xff) AM_READ(portff_r)
ADDRESS_MAP_END


/* Input ports */
static INPUT_PORTS_START( modellot )
INPUT_PORTS_END

READ8_MEMBER( modellot_state::port77_r)
{
	return 4;
}

READ8_MEMBER( modellot_state::portff_r)
{
	UINT8 data = (m_term_data) ? m_term_data ^ 0x7f : 0xff;
	m_term_data = 0;
	return data;
}

WRITE8_MEMBER( modellot_state::kbd_put )
{
	m_term_data = data;
}

void modellot_state::machine_reset()
{
	m_term_data = 1;
	m_p_chargen = memregion("chargen")->base();
	m_maincpu->set_state_int(Z80_PC, 0xe000);
}

const gfx_layout modellot_charlayout =
{
	8, 16,              /* 8x16 characters */
	128,                /* 128 characters */
	1,              /* 1 bits per pixel */
	{0},                /* no bitplanes; 1 bit per pixel */
	{0,1,2,3,4,5,6,7},
	{0, 8, 2 * 8, 3 * 8, 4 * 8, 5 * 8, 6 * 8, 7 * 8,
		0x400*8, 0x401*8, 0x402*8, 0x403*8, 0x404*8, 0x405*8, 0x406*8, 0x407*8},
	8*8             /* space between characters */
};

static GFXDECODE_START( modellot )
	GFXDECODE_ENTRY( "chargen", 0x0000, modellot_charlayout, 0, 1 )
GFXDECODE_END


UINT32 modellot_state::screen_update_modellot(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	UINT8 y,ra,chr,gfx,inv;
	UINT16 sy=0,ma=0,x;

	for (y = 0; y < 16; y++)
	{
		for (ra = 0; ra < 16; ra++)
		{
			UINT16 *p = &bitmap.pix16(sy++);

			for (x = 0; x < 64; x++)
			{
				inv = 0;

				chr = m_p_videoram[x+ma];

				if BIT(chr, 7) inv = 0xff;

				chr &= 0x7f; // cursor

				if (ra < 8)
					gfx = m_p_chargen[(chr<<3) | ra ];
				else
					gfx = m_p_chargen[(chr<<3) | (ra-8) | 0x400];

				gfx ^= inv;

				/* Display a scanline of a character */
				*p++ = BIT(gfx, 7);
				*p++ = BIT(gfx, 6);
				*p++ = BIT(gfx, 5);
				*p++ = BIT(gfx, 4);
				*p++ = BIT(gfx, 3);
				*p++ = BIT(gfx, 2);
				*p++ = BIT(gfx, 1);
				*p++ = BIT(gfx, 0);
			}
		}
		ma+=64;
	}
	return 0;
}

static MACHINE_CONFIG_START( modellot, modellot_state )
	/* basic machine hardware */
	MCFG_CPU_ADD("maincpu",Z80, XTAL_4MHz)
	MCFG_CPU_PROGRAM_MAP(modellot_mem)
	MCFG_CPU_IO_MAP(modellot_io)

	/* video hardware */
	MCFG_SCREEN_ADD_MONOCHROME("screen", RASTER, rgb_t::green)
	MCFG_SCREEN_REFRESH_RATE(50)
	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
	MCFG_SCREEN_SIZE(64*8, 16*16)
	MCFG_SCREEN_VISIBLE_AREA(0, 64*8-1, 0, 16*16-1)
	MCFG_SCREEN_UPDATE_DRIVER(modellot_state, screen_update_modellot)
	MCFG_SCREEN_PALETTE("palette")

	MCFG_GFXDECODE_ADD("gfxdecode", "palette", modellot )
	MCFG_PALETTE_ADD_MONOCHROME("palette")

	/* Devices */
	MCFG_DEVICE_ADD(KEYBOARD_TAG, GENERIC_KEYBOARD, 0)
	MCFG_GENERIC_KEYBOARD_CB(WRITE8(modellot_state, kbd_put))
MACHINE_CONFIG_END

/* ROM definition */
ROM_START( modellot )
	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
	//ROM_LOAD( "fdc8119.u3", 0x0000, 0x0400, CRC(a8aee944) SHA1(f2cc598ed2e7a1a620e2f3f53c1a573965f6af26))
	ROM_LOAD( "dt49-48.u1", 0xe000, 0x0400, CRC(2441c438) SHA1(832994a4214a744b7e19e5f74000c95ae65e3759))
	ROM_LOAD( "ht20.u2",    0xe400, 0x0400, CRC(497c0495) SHA1(d03beebc4c31284729f6eac3bdf1fbf44adf7fff))

	ROM_REGION( 0x0800, "chargen", ROMREGION_INVERT )
	ROM_LOAD( "gcem1.u3", 0x0000, 0x0200, CRC(e7739268) SHA1(091ef69282abe657d5f38c70a572964f5200a1d5))
	ROM_CONTINUE(0x400, 0x200)
	ROM_LOAD( "gcem2.u4", 0x0200, 0x0200, CRC(6614330e) SHA1(880a541fb0ef6f37ac89439f9ea75a313c3e53d6))
	ROM_CONTINUE(0x600, 0x200)
ROM_END

/* Driver */
COMP( 1979, modellot, 0, 0, modellot, modellot, driver_device, 0, "General Processor", "Modello T", MACHINE_IS_SKELETON)
