a2videoterm.cpp

// license:BSD-3-Clause
// copyright-holders:R. Belmont
/*********************************************************************

    a2videoterm.c

    Implementation of the Videx Videoterm 80-column card

    Notes (from Videoterm user's manual, which contains
           schematics and firmware source listings).

    C0nX: C0n0 is 6845 register address,
          C0n1 is 6845 register data.

          Bits 2 & 3 on any access to C0nX set the VRAM page at CC00.

    C800-CBFF: ROM
    CC00-CDFF: VRAM window

    TODO:
    Add font ROM select.

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

#include "emu.h"
#include "a2videoterm.h"

#include "video/mc6845.h"

#include "screen.h"


namespace {

/***************************************************************************
    PARAMETERS
***************************************************************************/

#define VIDEOTERM_ROM_REGION  "vterm_rom"
#define VIDEOTERM_GFX_REGION  "vterm_gfx"
#define VIDEOTERM_SCREEN_NAME "vterm_screen"
#define VIDEOTERM_MC6845_NAME "mc6845_vterm"

ROM_START( a2videoterm )
	ROM_REGION(0x800, VIDEOTERM_ROM_REGION, ROMREGION_ERASEFF)
	ROM_SYSTEM_BIOS(0, "v24_60hz", "Firmware v2.4 (60 Hz)")
	ROMX_LOAD( "6.ic6.bin", 0x000000, 0x000800, CRC(5776fa24) SHA1(19f69011ed7d2551c39d5c1cac1f5a2defc8f8fb), ROM_BIOS(0) ) // dumped from clone card
	ROM_SYSTEM_BIOS(1, "v24_50hz", "Firmware v2.4 (50 Hz)")
	ROMX_LOAD( "videx videoterm rom 2.4.bin", 0x000000, 0x000400, CRC(bbe3bb28) SHA1(bb653836e84850ce3197f461d4e19355f738cfbf), ROM_BIOS(1) )

	ROM_REGION(0x5800, VIDEOTERM_GFX_REGION, 0)
	ROM_LOAD( "videx videoterm character rom normal.bin", 0x000000, 0x000800, CRC(87f89f08) SHA1(410b54f33d13c82e3857f1be906d93a8c5b8d321) )
	//ROM_LOAD( "5.ic5.bin", 0x000000, 0x000800, CRC(aafa7085) SHA1(54d7c358f1927ba8f3b61145215a806d8cb6b673) ) // dumped from clone card, identical to normal ROM except final byte is FF instead of 00
	ROM_LOAD( "videx videoterm character rom normal uppercase.bin", 0x000800, 0x000800, CRC(3d94a7a4) SHA1(5518254f24bc945aab13bc71ecc9526d6dd8e033) )
	ROM_LOAD( "videx videoterm character rom apl.bin", 0x001000, 0x000800, CRC(1adb704e) SHA1(a95df910eca33188cacee333b1325aa47edbcc25) )
	ROM_LOAD( "videx videoterm character rom epson.bin", 0x001800, 0x000800, CRC(0c6ef8d0) SHA1(db72c0c120086f1aa4a87120c5d7993c4a9d3a18) )
	ROM_LOAD( "videx videoterm character rom french.bin", 0x002000, 0x000800, CRC(266aa837) SHA1(2c6b4e9d342dbb2de8e278740f11925a9d8c6616) )
	ROM_LOAD( "videx videoterm character rom german.bin", 0x002800, 0x000800, CRC(df7324fa) SHA1(0ce58d2ffadbebc8db9f85bbb9a08a4f142af682) )
	ROM_LOAD( "videx videoterm character rom katakana.bin", 0x003000, 0x000800, CRC(b728690e) SHA1(e018fa66b0ff560313bb35757c9ce7adecae0c3a) )
	ROM_LOAD( "videx videoterm character rom spanish.bin", 0x003800, 0x000800, CRC(439eac08) SHA1(d6f9f8eb7702440d9ae39129ea4f480b80fc4608) )
	ROM_LOAD( "videx videoterm character rom super and subscript.bin", 0x004000, 0x000800, CRC(08b7c538) SHA1(7f4029d97be05680fe695debe07cea07666419e0) )
	ROM_LOAD( "videx videoterm character rom symbol.bin", 0x004800, 0x000800, CRC(82bce582) SHA1(29dfa8c5257dbf25651c6bffa9cdb453482aa70e) )
	ROM_LOAD( "4.ic4.bin", 0x005000, 0x000800, CRC(8a497a48) SHA1(50c3df528109c65491a001ec74e50351a652c1fd) ) // dumped from clone card, contains inverse character set
ROM_END

ROM_START( a2ap16 )
	ROM_REGION(0x2000, VIDEOTERM_ROM_REGION, 0)
	ROM_LOAD( "space 84 video ap16.bin", 0x000000, 0x002000, CRC(0e188da2) SHA1(9a29250b6cc7b576fdc67769944de35e6f54b9d5) )

	ROM_REGION(0x4000, VIDEOTERM_GFX_REGION, 0)
	ROM_LOAD( "space 84 video chargen ap16.bin", 0x000000, 0x002000, CRC(b9447088) SHA1(19c95f91a67b948fc00a14621d574d629479d451) )
ROM_END

ROM_START( a2ap16alt )
	ROM_REGION(0x1000, VIDEOTERM_ROM_REGION, 0)
	ROM_LOAD( "unknown apple ii clone video 3.bin", 0x000000, 0x001000, CRC(af1226d2) SHA1(18a569f417a47f54a17bd9046d306a54b46ed049) )

	ROM_REGION(0x4000, VIDEOTERM_GFX_REGION, 0)
	ROM_LOAD( "unknown apple ii clone video 1.bin", 0x000000, 0x001000, CRC(cf84811c) SHA1(135f4f35607dd74941f0a3cae813227bf8a8a020) )
ROM_END

ROM_START( vtc1 )
	ROM_REGION(0x800, VIDEOTERM_ROM_REGION, 0)
	ROM_LOAD( "10.ic10.bin",  0x000000, 0x000800, CRC(ddbbc2fb) SHA1(15d6142b177b47c016f2745e1d95767b440d77c7) )

	ROM_REGION(0x1000, VIDEOTERM_GFX_REGION, 0)
	ROM_LOAD( "9.ic9.bin",    0x000000, 0x000800, CRC(094670f1) SHA1(aefae76fb07740d042cf294f01424efa7cc7a199) )
	ROM_LOAD( "8.ic8.bin",    0x000800, 0x000800, CRC(fbd98d77) SHA1(0d9b1c3917e23ca35d5fbd405f05ff6e87122b92) )
ROM_END

ROM_START( a2aevm80 )
	ROM_REGION(0x800, VIDEOTERM_ROM_REGION, 0)
	ROM_LOAD( "ae viewmaster 80 rom.bin", 0x000000, 0x000800, CRC(62a4b111) SHA1(159bf7c4add1435be215fddb648c0743fbcc49b5) )

	ROM_REGION(0x1000, VIDEOTERM_GFX_REGION, 0)
	ROM_LOAD( "ae viewmaster 80 video rom.bin", 0x000000, 0x000800, CRC(4801ab90) SHA1(f90658ffee7740f3cb30ecef2e151f7dc6098833) )
ROM_END

//**************************************************************************
//  TYPE DEFINITIONS
//**************************************************************************

class a2bus_videx80_device:
	public device_t,
	public device_a2bus_card_interface
{
protected:
	// construction/destruction
	a2bus_videx80_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock);

	virtual void device_start() override;
	virtual void device_reset() override;
	virtual void device_add_mconfig(machine_config &config) override;

	// overrides of standard a2bus slot functions
	virtual uint8_t read_c0nx(uint8_t offset) override;
	virtual void write_c0nx(uint8_t offset, uint8_t data) override;
	virtual uint8_t read_cnxx(uint8_t offset) override;
	virtual void write_cnxx(uint8_t offset, uint8_t data) override;
	virtual uint8_t read_c800(uint16_t offset) override;
	virtual void write_c800(uint16_t offset, uint8_t data) override;

	uint8_t m_ram[512*4];

	required_device<mc6845_device> m_crtc;
	required_region_ptr<uint8_t> m_rom, m_chrrom;

	MC6845_UPDATE_ROW(crtc_update_row);

	int m_rambank;
	uint8_t m_char_width;
};

class a2bus_videoterm_device : public a2bus_videx80_device
{
public:
	a2bus_videoterm_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	virtual const tiny_rom_entry *device_rom_region() const override;
};

class a2bus_ap16_device : public a2bus_videx80_device
{
public:
	a2bus_ap16_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	virtual void device_add_mconfig(machine_config &config) override;
	virtual const tiny_rom_entry *device_rom_region() const override;

protected:
	virtual uint8_t read_cnxx(uint8_t offset) override;
};


class a2bus_ap16alt_device : public a2bus_videx80_device
{
public:
	a2bus_ap16alt_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	virtual void device_add_mconfig(machine_config &config) override;
	virtual const tiny_rom_entry *device_rom_region() const override;

protected:
	virtual uint8_t read_cnxx(uint8_t offset) override;
};

class a2bus_vtc1_device : public a2bus_videx80_device
{
public:
	a2bus_vtc1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	virtual void device_add_mconfig(machine_config &config) override;
	virtual const tiny_rom_entry *device_rom_region() const override;
};

class a2bus_aevm80_device : public a2bus_videx80_device
{
public:
	a2bus_aevm80_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

	virtual void device_add_mconfig(machine_config &config) override;
	virtual const tiny_rom_entry *device_rom_region() const override;
};

/***************************************************************************
    FUNCTION PROTOTYPES
***************************************************************************/

//-------------------------------------------------
//  device_add_mconfig - add device configuration
//-------------------------------------------------

void a2bus_videx80_device::device_add_mconfig(machine_config &config)
{
	screen_device &screen(SCREEN(config, VIDEOTERM_SCREEN_NAME, SCREEN_TYPE_RASTER));
	screen.set_raw(17.43_MHz_XTAL, 1116, 0, 720, 260, 0, 216);
	//screen.set_raw(17.43_MHz_XTAL, 1107, 0, 720, 315, 0, 216);
	screen.set_screen_update(VIDEOTERM_MC6845_NAME, FUNC(mc6845_device::screen_update));

	HD6845S(config, m_crtc, 17.43_MHz_XTAL / 9);
	m_crtc->set_screen(VIDEOTERM_SCREEN_NAME);
	m_crtc->set_show_border_area(false);
	m_crtc->set_char_width(9);
	m_crtc->set_update_row_callback(FUNC(a2bus_videx80_device::crtc_update_row));
}

void a2bus_ap16_device::device_add_mconfig(machine_config &config)
{
	a2bus_videx80_device::device_add_mconfig(config);

	subdevice<screen_device>(VIDEOTERM_SCREEN_NAME)->set_raw(16_MHz_XTAL, 1026, 0, 720, 313, 0, 216);

	m_crtc->set_clock(16_MHz_XTAL / 9);
}

void a2bus_ap16alt_device::device_add_mconfig(machine_config &config)
{
	a2bus_videx80_device::device_add_mconfig(config);

	subdevice<screen_device>(VIDEOTERM_SCREEN_NAME)->set_raw(18_MHz_XTAL, 1152, 0, 720, 315, 0, 216);

	m_crtc->set_clock(18_MHz_XTAL / 9);
}

void a2bus_vtc1_device::device_add_mconfig(machine_config &config)
{
	a2bus_videx80_device::device_add_mconfig(config);

	subdevice<screen_device>(VIDEOTERM_SCREEN_NAME)->set_raw(18_MHz_XTAL, 1155, 0, 880, 260, 0, 216);

	m_crtc->set_clock(18_MHz_XTAL / 11);
	m_crtc->set_char_width(11);
}

void a2bus_aevm80_device::device_add_mconfig(machine_config &config)
{
	a2bus_videx80_device::device_add_mconfig(config);

	subdevice<screen_device>(VIDEOTERM_SCREEN_NAME)->set_raw(18_MHz_XTAL, 1280, 0, 800, 234, 0, 216);

	m_crtc->set_clock(18_MHz_XTAL / 10);
	m_crtc->set_char_width(10);
}

//-------------------------------------------------
//  rom_region - device-specific ROM region
//-------------------------------------------------

const tiny_rom_entry *a2bus_videoterm_device::device_rom_region() const
{
	return ROM_NAME( a2videoterm );
}

const tiny_rom_entry *a2bus_ap16_device::device_rom_region() const
{
	return ROM_NAME( a2ap16 );
}

const tiny_rom_entry *a2bus_ap16alt_device::device_rom_region() const
{
	return ROM_NAME( a2ap16alt );
}

const tiny_rom_entry *a2bus_vtc1_device::device_rom_region() const
{
	return ROM_NAME( vtc1 );
}

const tiny_rom_entry *a2bus_aevm80_device::device_rom_region() const
{
	return ROM_NAME( a2aevm80 );
}

//**************************************************************************
//  LIVE DEVICE
//**************************************************************************

a2bus_videx80_device::a2bus_videx80_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) :
	device_t(mconfig, type, tag, owner, clock),
	device_a2bus_card_interface(mconfig, *this),
	m_crtc(*this, VIDEOTERM_MC6845_NAME),
	m_rom(*this, VIDEOTERM_ROM_REGION),
	m_chrrom(*this, VIDEOTERM_GFX_REGION),
	m_rambank(0),
	m_char_width(9)
{
}

a2bus_videoterm_device::a2bus_videoterm_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	a2bus_videx80_device(mconfig, A2BUS_VIDEOTERM, tag, owner, clock)
{
}

a2bus_ap16_device::a2bus_ap16_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	a2bus_videx80_device(mconfig, A2BUS_IBSAP16, tag, owner, clock)
{
}

a2bus_ap16alt_device::a2bus_ap16alt_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	a2bus_videx80_device(mconfig, A2BUS_IBSAP16ALT, tag, owner, clock)
{
}

a2bus_vtc1_device::a2bus_vtc1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	a2bus_videx80_device(mconfig, A2BUS_VTC1, tag, owner, clock)
{
	m_char_width = 11;
}

a2bus_aevm80_device::a2bus_aevm80_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	a2bus_videx80_device(mconfig, A2BUS_AEVIEWMASTER80, tag, owner, clock)
{
	m_char_width = 10;
}

//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void a2bus_videx80_device::device_start()
{
	memset(m_ram, 0, 4*512);

	save_item(NAME(m_ram));
	save_item(NAME(m_rambank));
}

void a2bus_videx80_device::device_reset()
{
	m_rambank = 0;
}


/*-------------------------------------------------
    read_c0nx - called for reads from this card's c0nx space
-------------------------------------------------*/

uint8_t a2bus_videx80_device::read_c0nx(uint8_t offset)
{
	m_rambank = ((offset>>2) & 3) * 512;

	if (offset == 1)
	{
		return m_crtc->register_r();   // status_r?
	}

	return 0xff;
}


/*-------------------------------------------------
    write_c0nx - called for writes to this card's c0nx space
-------------------------------------------------*/

void a2bus_videx80_device::write_c0nx(uint8_t offset, uint8_t data)
{
	if (offset == 0)
	{
		m_crtc->address_w(data);
	}
	else if (offset == 1)
	{
		m_crtc->register_w(data);
	}

	m_rambank = ((offset>>2) & 3) * 512;
}

/*-------------------------------------------------
    read_cnxx - called for reads from this card's cnxx space
-------------------------------------------------*/

uint8_t a2bus_videx80_device::read_cnxx(uint8_t offset)
{
	return m_rom[offset+0x300];
}

uint8_t a2bus_ap16_device::read_cnxx(uint8_t offset)
{
	return m_rom[offset+0x1f00];
}

uint8_t a2bus_ap16alt_device::read_cnxx(uint8_t offset)
{
	return m_rom[offset+0xb00];
}

/*-------------------------------------------------
    write_cnxx - called for writes to this card's cnxx space
    the firmware writes here to switch in our $C800 a lot
-------------------------------------------------*/
void a2bus_videx80_device::write_cnxx(uint8_t offset, uint8_t data)
{
}

/*-------------------------------------------------
    read_c800 - called for reads from this card's c800 space
-------------------------------------------------*/

uint8_t a2bus_videx80_device::read_c800(uint16_t offset)
{
	// ROM at c800-cbff
	// bankswitched RAM at cc00-cdff
	if (offset < 0x400)
	{
//        printf("Read VRAM at %x = %02x\n", offset+m_rambank, m_ram[offset + m_rambank]);
		return m_rom[offset];
	}
	else
	{
		return m_ram[(offset-0x400) + m_rambank];
	}
}

/*-------------------------------------------------
    write_c800 - called for writes to this card's c800 space
-------------------------------------------------*/
void a2bus_videx80_device::write_c800(uint16_t offset, uint8_t data)
{
	if (offset >= 0x400)
	{
//        printf("%02x to VRAM at %x\n", data, offset-0x400+m_rambank);
		m_ram[(offset-0x400) + m_rambank] = data;
	}
}

MC6845_UPDATE_ROW( a2bus_videx80_device::crtc_update_row )
{
	uint32_t  *p = &bitmap.pix(y);
	uint16_t  chr_base = ra; //( ra & 0x08 ) ? 0x800 | ( ra & 0x07 ) : ra;

	for (int i = 0; i < x_count; i++)
	{
		uint16_t offset = ( ma + i ) & 0x7ff;
		uint8_t chr = m_ram[ offset ];
		uint8_t data = m_chrrom[ chr_base + chr * 16 ];
		rgb_t fg = rgb_t::white();
		rgb_t bg = rgb_t::black();

		if ( i == cursor_x )
			std::swap(fg, bg);

		for (int j = m_char_width; j > 0; j--)
		{
			*p++ = BIT(data, 7) ? fg : bg;
			data <<= 1;
		}
	}
}

} // anonymous namespace


//**************************************************************************
//  GLOBAL VARIABLES
//**************************************************************************

DEFINE_DEVICE_TYPE_PRIVATE(A2BUS_VIDEOTERM,      device_a2bus_card_interface, a2bus_videoterm_device, "a2vidtrm", "Videx Videoterm 80 Column Display")
DEFINE_DEVICE_TYPE_PRIVATE(A2BUS_IBSAP16,        device_a2bus_card_interface, a2bus_ap16_device,      "a2ap16",   "IBS AP-16 80 column card")
DEFINE_DEVICE_TYPE_PRIVATE(A2BUS_IBSAP16ALT,     device_a2bus_card_interface, a2bus_ap16alt_device,   "a2ap16a",  "IBS AP-16 80 column card (alt. version)")
DEFINE_DEVICE_TYPE_PRIVATE(A2BUS_VTC1,           device_a2bus_card_interface, a2bus_vtc1_device,      "a2vtc1",   "unknown Videoterm clone")
DEFINE_DEVICE_TYPE_PRIVATE(A2BUS_AEVIEWMASTER80, device_a2bus_card_interface, a2bus_aevm80_device,    "a2aevm80", "Applied Engineering Viewmaster 80")