m79152pc: Add cursor, scrolling support and some video attributes

src/mame/drivers/m79152pc.cpp

@@ -2,11 +2,21 @@
 // copyright-holders:Miodrag Milanovic,AJR
 /***************************************************************************
 
-        Mera-Elzab 79152pc
+    Mera-Elzab 79152pc
 
-        This is terminal
+    This system provides a half-featured emulation of the ADM-3A or similar
+    terminals by TeleVideo and Wyse. The “half-featured” part is that some
+    commands are not recognized at all and others are merely filtered out.
 
-        29/12/2011 Skeleton driver.
+    The 8035 here serves as a soft CRTC, counting horizontal scans and
+    outputting row addresses (dependent on scrolling) and vertical sync
+    pulses. The present emulation produces incorrect video output at the
+    vertical margins and is extremely prone to desyncing.
+
+    “PC Shadow” is the name of the software this terminal either runs or
+    interfaces with. The actual keyboard is unknown, but is almost
+    certainly PC-XT compatible. The character set is a nonstandard variant
+    of CP 437 that incorporates a few Polish letters.
 
 ****************************************************************************/
 
@@ -31,36 +41,59 @@ class m79152pc_state : public driver_device
 public:
 	m79152pc_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_p_videoram(*this, "videoram")
+		, m_videoram(*this, "videoram")
-		, m_p_attributes(*this, "attributes")
+		, m_attributes(*this, "attributes")
+		, m_chargen(*this, "chargen")
 		, m_maincpu(*this, "maincpu")
-		, m_p_chargen(*this, "chargen")
+		, m_mcu(*this, "mcu")
 		, m_uart(*this, "uart")
+		, m_screen(*this, "screen")
 		, m_beep(*this, "beep")
 	{ }
 
 	void m79152pc(machine_config &config);
 
+protected:
+	virtual void machine_start() override;
+
 private:
 	DECLARE_WRITE8_MEMBER(beep_w);
 	DECLARE_WRITE_LINE_MEMBER(latch_full_w);
 	DECLARE_READ_LINE_MEMBER(mcu_t0_r);
+	DECLARE_READ_LINE_MEMBER(mcu_t1_r);
+	void mcu_p1_w(u8 data);
+	void mcu_p2_w(u8 data);
+	void lc_reset_w(u8 data);
 
-	uint32_t screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+	TIMER_CALLBACK_MEMBER(hsync_on);
+	TIMER_CALLBACK_MEMBER(hsync_off);
+
+	u32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+	void screen_draw_line(bitmap_ind16 &bitmap, unsigned y);
 
 	void mem_map(address_map &map);
 	void io_map(address_map &map);
 	void mcu_map(address_map &map);
 	void mcu_io_map(address_map &map);
 
-	required_shared_ptr<uint8_t> m_p_videoram;
+	required_shared_ptr<u8> m_videoram;
-	required_shared_ptr<uint8_t> m_p_attributes;
+	required_shared_ptr<u8> m_attributes;
+	required_region_ptr<u8> m_chargen;
+
 	required_device<z80_device> m_maincpu;
-	required_region_ptr<u8> m_p_chargen;
+	required_device<mcs48_cpu_device> m_mcu;
 	required_device<z80sio_device> m_uart;
+	required_device<screen_device> m_screen;
 	required_device<beep_device> m_beep;
 
+	u8 m_line_base;
+	u8 m_line_count;
 	bool m_latch_full;
+	u8 m_mcu_p2;
+	bool m_hsync;
+
+	emu_timer *m_hsync_on_timer;
+	emu_timer *m_hsync_off_timer;
 };
 
 WRITE8_MEMBER(m79152pc_state::beep_w)
@@ -78,6 +111,26 @@ READ_LINE_MEMBER(m79152pc_state::mcu_t0_r)
 	return m_latch_full ? 0 : 1;
 }
 
+READ_LINE_MEMBER(m79152pc_state::mcu_t1_r)
+{
+	return m_hsync ? 0 : 1;
+}
+
+void m79152pc_state::mcu_p1_w(u8 data)
+{
+	m_line_base = data;
+}
+
+void m79152pc_state::mcu_p2_w(u8 data)
+{
+	m_mcu_p2 = data;
+}
+
+void m79152pc_state::lc_reset_w(u8 data)
+{
+	m_line_count = (data >> 4) & 0xf;
+}
+
 void m79152pc_state::mem_map(address_map &map)
 {
 	map.unmap_value_high();
@@ -106,7 +159,7 @@ void m79152pc_state::mcu_map(address_map &map)
 
 void m79152pc_state::mcu_io_map(address_map &map)
 {
-	map(0x00, 0x00).mirror(0xff).r("mculatch", FUNC(i8212_device::read));
+	map(0x00, 0x00).mirror(0xff).r("mculatch", FUNC(i8212_device::read)).w(FUNC(m79152pc_state::lc_reset_w));
 }
 
 /* Input ports */
@@ -114,37 +167,55 @@ static INPUT_PORTS_START( m79152pc )
 INPUT_PORTS_END
 
 
-uint32_t m79152pc_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
+TIMER_CALLBACK_MEMBER(m79152pc_state::hsync_on)
 {
-// Attributes are unknown so are not implemented
+	m_screen->update_now();
-	uint8_t y,ra,chr,gfx; //,attr;
+	m_mcu->set_input_line(MCS48_INPUT_IRQ, ASSERT_LINE);
-	uint16_t sy=0,ma=0,x;
+	m_hsync = true;
+	m_line_count = (m_line_count + 1) & 0xf;
+}
 
-	for (y = 0; y < 25; y++)
+TIMER_CALLBACK_MEMBER(m79152pc_state::hsync_off)
+{
+	unsigned vpos = m_screen->vpos();
+	m_mcu->set_input_line(MCS48_INPUT_IRQ, CLEAR_LINE);
+	m_hsync_on_timer->adjust(m_screen->time_until_pos(vpos, 640));
+	m_hsync = false;
+}
+
+void m79152pc_state::screen_draw_line(bitmap_ind16 &bitmap, unsigned y)
+{
+	u16 ma = u16(m_line_base) << 4;
+	u8 ra = m_line_count & 0xf;
+
+	u16 *p = &bitmap.pix16(y++);
+
+	for (u16 x = ma; x < ma + 80; x++)
 	{
-		for (ra = 0; ra < 12; ra++)
+		// BIT(attr, 3) should probably be blinking
-		{
+		// BIT(attr, 1) may be used for high-intensity text (
-			uint16_t *p = &bitmap.pix16(sy++);
+		u8 chr = m_videoram[x];
+		u8 attr = m_attributes[x];
+		u8 gfx = m_chargen[(chr << 4) | (BIT(attr, 2) && ra == 15 ? 3 : ra)];
+		if (BIT(attr, 0))
+			gfx ^= 0xff;
 
-			for (x = ma; x < ma + 80; x++)
+		*p++ = BIT(gfx, 7);
-			{
+		*p++ = BIT(gfx, 6);
-				chr = m_p_videoram[x];
+		*p++ = BIT(gfx, 5);
-				//attr = m_p_attributes[x];
+		*p++ = BIT(gfx, 4);
-				gfx = m_p_chargen[((chr<<4) | ra) + 4 ];
+		*p++ = BIT(gfx, 3);
-
+		*p++ = BIT(gfx, 2);
-				/* Display a scanline of a character */
+		*p++ = BIT(gfx, 1);
-				*p++ = BIT(gfx, 7);
+		*p++ = BIT(gfx, 0);
-				*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+=80;
 	}
+}
+
+u32 m79152pc_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
+{
+	for (unsigned y = cliprect.top(); y <= cliprect.bottom(); y++)
+		screen_draw_line(bitmap, y);
+
 	return 0;
 }
 
@@ -166,6 +237,26 @@ static GFXDECODE_START( gfx_m79152pc )
 	GFXDECODE_ENTRY( "chargen", 0x0000, m79152pc_charlayout, 0, 1 )
 GFXDECODE_END
 
+
+void m79152pc_state::machine_start()
+{
+	m_latch_full = false;
+	m_mcu_p2 = 0xff;
+	m_line_base = 0;
+	m_line_count = 0;
+	m_hsync = false;
+
+	m_hsync_on_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(m79152pc_state::hsync_on), this));
+	m_hsync_off_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(m79152pc_state::hsync_off), this));
+	m_hsync_off_timer->adjust(m_screen->time_until_pos(9, 0), 0, m_screen->scan_period());
+
+	save_item(NAME(m_latch_full));
+	save_item(NAME(m_mcu_p2));
+	save_item(NAME(m_line_base));
+	save_item(NAME(m_line_count));
+	save_item(NAME(m_hsync));
+}
+
 static const z80_daisy_config daisy_chain[] =
 {
 	{ "ctc" },
@@ -180,20 +271,21 @@ MACHINE_CONFIG_START(m79152pc_state::m79152pc)
 	m_maincpu->set_addrmap(AS_IO, &m79152pc_state::io_map);
 	m_maincpu->set_daisy_config(daisy_chain);
 
-	mcs48_cpu_device &mcu(I8035(config, "mcu", 6'000'000)); // NEC D8035HLC
+	I8035(config, m_mcu, 6'000'000); // NEC D8035HLC
-	mcu.set_addrmap(AS_PROGRAM, &m79152pc_state::mcu_map);
+	m_mcu->set_addrmap(AS_PROGRAM, &m79152pc_state::mcu_map);
-	mcu.set_addrmap(AS_IO, &m79152pc_state::mcu_io_map);
+	m_mcu->set_addrmap(AS_IO, &m79152pc_state::mcu_io_map);
-	mcu.t0_in_cb().set(FUNC(m79152pc_state::mcu_t0_r));
+	m_mcu->t0_in_cb().set(FUNC(m79152pc_state::mcu_t0_r));
+	m_mcu->t1_in_cb().set(FUNC(m79152pc_state::mcu_t1_r));
+	m_mcu->p1_out_cb().set(FUNC(m79152pc_state::mcu_p1_w));
+	m_mcu->p2_out_cb().set(FUNC(m79152pc_state::mcu_p2_w));
+	m_mcu->p2_out_cb().append("ctc", FUNC(z80ctc_device::trg0)).bit(6); // determines beep duration
+	m_mcu->p2_out_cb().append("ctc", FUNC(z80ctc_device::trg3)).bit(6);
 
 	/* video hardware */
-	MCFG_SCREEN_ADD("screen", RASTER)
+	SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
-	MCFG_SCREEN_REFRESH_RATE(50)
+	m_screen->set_raw(50 * 720 * 324, 720, 0, 640, 324, 0, 250);
-	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
+	m_screen->set_screen_update(FUNC(m79152pc_state::screen_update));
-	MCFG_SCREEN_SIZE(640, 300)
+	m_screen->set_palette("palette");
-	MCFG_SCREEN_VISIBLE_AREA(0, 640-1, 0, 300-1)
-	MCFG_SCREEN_UPDATE_DRIVER(m79152pc_state, screen_update)
-	MCFG_SCREEN_PALETTE("palette")
-	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE("ctc", z80ctc_device, trg0)) // determines beep duration (probably too slow)
 
 	MCFG_DEVICE_ADD("gfxdecode", GFXDECODE, "palette", gfx_m79152pc)
 	MCFG_PALETTE_ADD_MONOCHROME("palette")
@@ -219,6 +311,8 @@ MACHINE_CONFIG_START(m79152pc_state::m79152pc)
 	ctc.zc_callback<2>().set(m_uart, FUNC(z80sio_device::txca_w));
 	ctc.zc_callback<2>().append(m_uart, FUNC(z80sio_device::rxca_w));
 
+	// FIXME: Channel A should be the modem channel. Channel B should be a PC keyboard
+	// that outputs XT scancodes, which are then rebroadcast through channel A!
 	Z80SIO(config, m_uart, 4'000'000); // UB8560D
 	m_uart->out_int_callback().set_inputline(m_maincpu, INPUT_LINE_IRQ0);
 	m_uart->out_txda_callback().set("keyboard", FUNC(rs232_port_device::write_txd));
@@ -250,6 +344,9 @@ ROM_START( m79152pc )
 
 	ROM_REGION( 0x0800, "mcu", 0 )
 	ROM_LOAD( "char.bin",  0x0000, 0x0800, CRC(da3792a5) SHA1(b4a4f0d61d8082b7909a346a5b01494c53cf8d05))
+
+	ROM_REGION( 0x0200, "proms", 0 )
+	ROM_LOAD( "7641apc.bin", 0x0000, 0x0200, NO_DUMP)
 ROM_END
 
 /* Driver */