brother/pn8800fxb: Major improvements

* Add timer interrupt
* Add keyboard emulation
* Improve video emulation, support more modes
* Cleanup low memory emulation

src/mame/brother/pn8800fxb.cpp

@@ -17,16 +17,27 @@
     - XTAL XT5 16.0MHz (near FDC)
 
     TODO:
-    - Almost everything, draws the initial screen
+    - Fix ROM banking (ROM self-test shows NG)
+    - Improve video emulation (offset, modes, etc.)
+    - RTC
+    - Floppy
+    - Buzzer
+    - Centronics
+    - Modem
+    - Soft power off/on
+    - RAM contents should be retained when turning off
+    - Bookman (unlikely to make progress, extra PCB contains custom CPU)
 
     Notes:
     - There is a serially connected daughterbord containing the Bookman logic
+    - Press CODE+SHIFT+BS on the main menu for a self-test screen
 
 ****************************************************************************/
 
 #include "emu.h"
 
 #include "cpu/z180/z180.h"
+#include "machine/timer.h"
 
 #include "emupal.h"
 #include "screen.h"
@@ -46,7 +57,9 @@ public:
 		m_maincpu(*this, "maincpu"),
 		m_rombank(*this, "rombank"),
 		m_palette(*this, "palette"),
-		m_gfxdecode(*this, "gfxdecode")
+		m_gfxdecode(*this, "gfxdecode"),
+		m_keys(*this, "KO%u", 0U),
+		m_lomem_view(*this, "lomem")
 	{ }
 
 	void pn8800fxb(machine_config &config);
@@ -60,29 +73,43 @@ private:
 	required_memory_bank m_rombank;
 	required_device<palette_device> m_palette;
 	required_device<gfxdecode_device> m_gfxdecode;
+	required_ioport_array<9> m_keys;
+	memory_view m_lomem_view;
+
+	uint8_t m_key_select;
 
 	std::unique_ptr<uint8_t[]> m_vram;
+	uint16_t m_cursor_addr;
 	uint16_t m_video_addr;
 	uint8_t m_video_ctrl;
+	uint8_t m_video_offset;
+	uint8_t m_cursor_ctrl;
 	uint8_t m_mem_change;
 
 	void mem_map(address_map &map);
 	void io_map(address_map &map);
 
+	uint8_t keyboard_r();
+	void keyboard_w(uint8_t data);
+
 	void palette(palette_device &palette) const;
 	uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 
+	void cursor_addr_lo_w(uint8_t data);
+	void cursor_addr_hi_w(uint8_t data);
 	void video_addr_lo_w(uint8_t data);
 	void video_addr_hi_w(uint8_t data);
 	uint8_t video_data_r();
 	void video_data_w(uint8_t data);
 	uint8_t video_ctrl_r();
 	void video_ctrl_w(uint8_t data);
+	void video_offset_w(uint8_t data);
+	void cursor_ctrl_w(uint8_t data);
 
 	void mem_change_w(uint8_t data);
 	void bank_select_w(uint8_t data);
-	uint8_t lo_mem_r(offs_t offset);
+	void int_ack_w(uint8_t data);
-	void lo_mem_w(offs_t offset, uint8_t data);
+	TIMER_DEVICE_CALLBACK_MEMBER(int1_timer);
 };
 
 
@@ -93,43 +120,49 @@ private:
 void pn8800fxb_state::mem_map(address_map &map)
 {
 	map(0x00000, 0x01fff).rom();
-	map(0x02000, 0x07fff).rw(FUNC(pn8800fxb_state::lo_mem_r), FUNC(pn8800fxb_state::lo_mem_w));
+	map(0x02000, 0x05fff).ram().share("window1");
+	map(0x06000, 0x07fff).view(m_lomem_view);
+	m_lomem_view[0](0x06000, 0x07fff).ram().share("window2");
+	m_lomem_view[1](0x06000, 0x07fff).rom().region("maincpu", 0x06000);
 	map(0x08000, 0x3ffff).rom();
 	map(0x40000, 0x41fff).unmaprw();
-	map(0x42000, 0x45fff).rom().region("maincpu", 0x2000);
+	map(0x42000, 0x45fff).rom().region("maincpu", 0x02000);
 	map(0x46000, 0x4ffff).unmaprw();
 	map(0x50000, 0x5ffff).bankr(m_rombank);
-	map(0x60000, 0x7ffff).ram();
+	map(0x60000, 0x61fff).ram();
+	map(0x62000, 0x65fff).ram().share("window1");
+	map(0x66000, 0x67fff).ram().share("window2");
+	map(0x68000, 0x7ffff).ram();
 }
 
 void pn8800fxb_state::io_map(address_map &map)
 {
 	map.global_mask(0xff);
 	map(0x00, 0x3f).noprw(); // z180 internal
-	// 70 cursor
+	map(0x70, 0x70).w(FUNC(pn8800fxb_state::cursor_addr_lo_w));
-	// 71 cursor
+	map(0x71, 0x71).w(FUNC(pn8800fxb_state::cursor_addr_hi_w));
 	map(0x72, 0x72).w(FUNC(pn8800fxb_state::video_addr_lo_w));
 	map(0x73, 0x73).w(FUNC(pn8800fxb_state::video_addr_hi_w));
 	map(0x74, 0x74).rw(FUNC(pn8800fxb_state::video_data_r), FUNC(pn8800fxb_state::video_data_w));
 	map(0x75, 0x75).rw(FUNC(pn8800fxb_state::video_ctrl_r), FUNC(pn8800fxb_state::video_ctrl_w));
-	// 76 display offset
+	map(0x76, 0x76).w(FUNC(pn8800fxb_state::video_offset_w));
-	// 77 cursor control
+	map(0x77, 0x77).w(FUNC(pn8800fxb_state::cursor_ctrl_w));
 	// 78-7f mode select
 	// 80-87 fdc
 	// 88-8f input
 	map(0x90, 0x90).mirror(0x07).w(FUNC(pn8800fxb_state::mem_change_w));
 	// 98-9f rs break
 	// a0-a7 rs232
-	// a8-af not used
+	map(0xa8, 0xa8).mirror(0x07).nopr(); // "not used" - but read often
 	// b0-b7 power supply
-	// b8-bf keyboard
+	map(0xb8, 0xb8).rw(FUNC(pn8800fxb_state::keyboard_r), FUNC(pn8800fxb_state::keyboard_w));
 	// c0-c7 cdcc data
 	// c8-cf cdcc control
-	// d0-df rtc
+	map(0xd0, 0xdf).noprw(); // rtc
 	map(0xe0, 0xe0).mirror(0x07).w(FUNC(pn8800fxb_state::bank_select_w));
 	// e8-ef ga test
 	// f0-f7 buzzer
-	// f8-ff interrupt ack
+	map(0xf8, 0xf8).mirror(0x07).w(FUNC(pn8800fxb_state::int_ack_w));
 }
 
 
@@ -138,8 +171,112 @@ void pn8800fxb_state::io_map(address_map &map)
 //**************************************************************************
 
 static INPUT_PORTS_START( pn8800fxb )
+	PORT_START("KO0")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_LSHIFT)    PORT_CODE(KEYCODE_RSHIFT)      PORT_CHAR(UCHAR_SHIFT_1)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_LEFT)      PORT_CHAR(UCHAR_MAMEKEY(LEFT)) PORT_NAME("\xe2\x86\x90  EXPR") // ←
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_BACKSPACE) PORT_CHAR(8)                   PORT_NAME("BS")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_ENTER)     PORT_CHAR(13)                  PORT_NAME("RETURN  IND CLR  =")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_UP)        PORT_CHAR(UCHAR_MAMEKEY(UP))   PORT_NAME("\xe2\x86\x91  PRE S") // ↑
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_SPACE)     PORT_CHAR(' ')
+
+	PORT_START("KO1")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_CLOSEBRACE) PORT_CHAR('[') PORT_CHAR(']') PORT_NAME(u8"[  ]  ½  ¼")
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_EQUALS)     PORT_CHAR('=') PORT_CHAR('+') PORT_NAME("=  +  L OUT")
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_0)          PORT_CHAR('0') PORT_CHAR(')') PORT_NAME("0  )  W OUT")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_MINUS)      PORT_CHAR('-') PORT_CHAR('_') PORT_NAME("-  _  -")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_P)          PORT_CHAR('p') PORT_CHAR('P') PORT_NAME("p  P  PRINT  +")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_SLASH)      PORT_CHAR('/') PORT_CHAR('?') PORT_NAME("/  ?  /")
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("KO2")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_DOWN)  PORT_CHAR(UCHAR_MAMEKEY(DOWN))                 PORT_NAME("\xe2\x86\x93  NEXT S") // ↓
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_QUOTE) PORT_CHAR('\'') PORT_CHAR('"')
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_L)     PORT_CHAR('l')  PORT_CHAR('L')                 PORT_NAME("l  L  L IND  3")
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_9)     PORT_CHAR('9')  PORT_CHAR('(')                 PORT_NAME("9  (  T CLR  9")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_O)     PORT_CHAR('o')  PORT_CHAR('O')                 PORT_NAME("o  O  JUST  6")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_STOP)  PORT_CHAR('.')  PORT_CHAR('>')  PORT_CHAR(']') PORT_NAME(".  >  ]  .")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_COLON) PORT_CHAR(';')  PORT_CHAR(':')                 PORT_NAME(";  :  *")
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_RIGHT) PORT_CHAR(UCHAR_MAMEKEY(RIGHT))                PORT_NAME("\xe2\x86\x92  RELOC") // →
+
+	PORT_START("KO3")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_K)     PORT_CHAR('k') PORT_CHAR('K')                PORT_NAME("k  K  KB  2")
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_8)     PORT_CHAR('8') PORT_CHAR('*')                PORT_NAME("8  *  DT SET  8")
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_6)     PORT_CHAR('6') PORT_CHAR('^')
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_7)     PORT_CHAR('7') PORT_CHAR('&')                PORT_NAME("7  &  T SET  7")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_I)     PORT_CHAR('i') PORT_CHAR('I')                PORT_NAME("i  I  INSERT  5")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_COMMA) PORT_CHAR(',') PORT_CHAR('<') PORT_CHAR('[')
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("KO4")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_N) PORT_CHAR('n') PORT_CHAR('N')
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_J) PORT_CHAR('j') PORT_CHAR('J')                PORT_NAME("j  J  LAYOUT  1")
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_Y) PORT_CHAR('y') PORT_CHAR('Y') PORT_CHAR('{') PORT_NAME("y  Y  {  <")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_U) PORT_CHAR('u') PORT_CHAR('U') PORT_CHAR('}') PORT_NAME("u  U  }  >")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_H) PORT_CHAR('h') PORT_CHAR('H')                PORT_NAME("h  H  HELP")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_M) PORT_CHAR('m') PORT_CHAR('M')                PORT_NAME("m  M  M CODE  0")
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("KO5")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_B) PORT_CHAR('b') PORT_CHAR('B')
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_F) PORT_CHAR('f') PORT_CHAR('F')
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_T) PORT_CHAR('t') PORT_CHAR('T')                PORT_NAME("t  T  TEMP")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_R) PORT_CHAR('r') PORT_CHAR('R')
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_G) PORT_CHAR('g') PORT_CHAR('G')                PORT_NAME("g  G  GOTO")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_V) PORT_CHAR('v') PORT_CHAR('V') PORT_CHAR(U'`')
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("KO6")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_ESC)  PORT_CHAR(27)                 PORT_NAME("CANCEL")
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_D)    PORT_CHAR('d') PORT_CHAR('D')
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_3)    PORT_CHAR('3') PORT_CHAR('#') PORT_NAME("3  #  M REL")
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_5)    PORT_CHAR('5') PORT_CHAR('%') PORT_NAME("5  %  R MAR")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_4)    PORT_CHAR('4') PORT_CHAR('$') PORT_NAME("4  $  L MAR")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_E)    PORT_CHAR('e') PORT_CHAR('E')
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_C)    PORT_CHAR('c') PORT_CHAR('C')
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_LALT)                               PORT_NAME("MENU  FILE")
+
+	PORT_START("KO7")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_X)   PORT_CHAR('x') PORT_CHAR('X') PORT_CHAR('|')  PORT_NAME(u8"x  X  |  ²")
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_W)   PORT_CHAR('w') PORT_CHAR('W') PORT_CHAR(U'¢')
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_TAB) PORT_CHAR(9)                                  PORT_NAME("TAB  P IND")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_2)   PORT_CHAR('2') PORT_CHAR('@')                 PORT_NAME("2  @  LINE")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_S)   PORT_CHAR('s') PORT_CHAR('S')                 PORT_NAME("s  S  CALC")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("KO8")
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_UNUSED)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_A)        PORT_CHAR('a')    PORT_CHAR('A')                 PORT_NAME("a  A  ABBR")
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_Q)        PORT_CHAR('q')    PORT_CHAR('Q')
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_TILDE)    PORT_CHAR(U'`')   PORT_CHAR('~')                 PORT_NAME(u8"`  ~  SPELL  ±  °")
+	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_1)        PORT_CHAR('1')    PORT_CHAR('!')                 PORT_NAME("1  !  PITCH")
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_CAPSLOCK) PORT_CHAR(UCHAR_MAMEKEY(CAPSLOCK))               PORT_NAME("CAPS  SHIFT LOCK")
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_Z)        PORT_CHAR('z')    PORT_CHAR('Z') PORT_CHAR('\\') PORT_NAME(u8"z  Z  \\  §")
+	PORT_BIT(0x80, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_CODE(KEYCODE_LCONTROL) PORT_CHAR(UCHAR_SHIFT_2)                         PORT_NAME("CODE")
 INPUT_PORTS_END
 
+uint8_t pn8800fxb_state::keyboard_r()
+{
+	if (m_key_select < 9)
+		return m_keys[m_key_select]->read();
+	else
+		logerror("keyboard_r from %02x\n", m_key_select);
+
+	return 0xff;
+}
+
+void pn8800fxb_state::keyboard_w(uint8_t data)
+{
+	m_key_select = data;
+}
+
 
 //**************************************************************************
 //  VIDEO EMULATION
@@ -147,8 +284,8 @@ INPUT_PORTS_END
 
 void pn8800fxb_state::palette(palette_device &palette) const
 {
-	palette.set_pen_color(0, rgb_t(131, 238, 47));
+	palette.set_pen_color(0, rgb_t(86, 228, 94));
-	palette.set_pen_color(1, rgb_t(31, 84, 67));
+	palette.set_pen_color(1, rgb_t(58, 86, 143));
 }
 
 uint32_t pn8800fxb_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
@@ -157,26 +294,99 @@ uint32_t pn8800fxb_state::screen_update(screen_device &screen, bitmap_rgb32 &bit
 
 	const pen_t *const pen = m_palette->pens();
 
-	for (int y = 0; y < 22; y++)
+	// 22 line text mode doesn't cover the full screen
+	bitmap.fill(pen[0], cliprect);
+
+	if (BIT(m_video_ctrl, 0))
 	{
-		for (int x = 0; x < 80; x++)
+		if (BIT(m_video_ctrl, 3))
 		{
-			//uint8_t attr = m_vram[y * 0x100 + x * 2 + 0];
+			// graphics mode
-			uint8_t code = m_vram[y * 0x100 + x * 2 + 1];
+			uint8_t *vram = m_vram.get();
 
-			// draw 9 lines
+			// left 512 pixels of screen
-			for (int l = 0; l < 9; l++)
+			for (int y = 0; y < 200; y++)
+				for (int x = 0; x < 512; x += 8, vram++)
+					for (int p = 0; p < 8; p++)
+						bitmap.pix(y, x + p) = pen[BIT(*vram, 7 - p)];
+
+			// right 128 pixels of screen
+			for (int y = 0; y < 200; y++)
+				for (int x = 0; x < 128; x += 8, vram++)
+					for (int p = 0; p < 8; p++)
+						bitmap.pix(y, 512 + x + p) = pen[BIT(*vram, 7 - p)];
+		}
+		else
+		{
+			// text mode
+			int lines = BIT(m_video_ctrl, 5) ? 25 : 22;
+
+			for (int y = 0; y < lines; y++)
 			{
-				uint8_t data = 0x00;
+				for (int x = 0; x < 80; x++)
-
-				// line 9 always blank?
-				if (l < 8)
-					data = m_vram[0x3000 + (code << 3) + l];
-
-				// draw 8 pixels of the character
-				for (int b = 0; b < 8; b++)
 				{
-					bitmap.pix(y * 9 + l, x * 8 + b) = pen[BIT(data, 7 - b)];
+					// attributes
+					//
+					// 7-------  unknown
+					// -6------  subscript
+					// --5-----  superscript
+					// ---4----  invert
+					// ----3---  vertical line
+					// -----2--  code high bit
+					// ------1-  overline
+					// -------0  underline
+
+					uint8_t attr = m_vram[y * 0x100 + x * 2 + 0];
+					uint16_t code = m_vram[y * 0x100 + x * 2 + 1];
+
+					// apply code high bit (high table contains bold characters)
+					code |= (BIT(attr, 2) << 8) | code;
+
+					bool cursor_active = (y * 0x100 + x * 2) == (m_cursor_addr << 1);
+
+					// draw 8 or 9 lines
+					for (int l = 0; l < 9; l++)
+					{
+						uint8_t data = 0x00;
+
+						// skip empty line in 25 line mode
+						if (lines == 25 && l == 0)
+							continue;
+
+						// character data (or cursor) in lines 1 to 8
+						if (l > 0)
+						{
+							if (cursor_active)
+								data = 0xff;
+							else
+								data = m_vram[0x3000 + (code << 3) + l - 1];
+						}
+
+						// underline?
+						if (BIT(attr, 0) && l == 8)
+							data = 0xff;
+
+						// overline?
+						if (BIT(attr, 1) && l == 0)
+							data = 0xff;
+
+						// vertical line?
+						if (BIT(attr, 3))
+							data |= 0x01;
+
+						// invert?
+						if (BIT(attr, 4))
+							data ^= 0xff;
+
+						// draw 8 pixels of the character
+						for (int b = 0; b < 8; b++)
+						{
+							if (lines == 25)
+								bitmap.pix(y * 8 + l - 1, x * 8 + b) = pen[BIT(data, 7 - b)];
+							else
+								bitmap.pix(y * 9 + l, x * 8 + b) = pen[BIT(data, 7 - b)];
+						}
+					}
 				}
 			}
 		}
@@ -185,6 +395,17 @@ uint32_t pn8800fxb_state::screen_update(screen_device &screen, bitmap_rgb32 &bit
 	return 0;
 }
 
+void pn8800fxb_state::cursor_addr_lo_w(uint8_t data)
+{
+	m_cursor_addr = (m_cursor_addr & 0xff00) | (data << 0);
+}
+
+void pn8800fxb_state::cursor_addr_hi_w(uint8_t data)
+{
+	data &= 0x0f;
+	m_cursor_addr = (data << 8) | (m_cursor_addr & 0x00ff);
+}
+
 void pn8800fxb_state::video_addr_lo_w(uint8_t data)
 {
 	m_video_addr = (m_video_addr & 0xff00) | (data << 0);
@@ -213,8 +434,8 @@ uint8_t pn8800fxb_state::video_ctrl_r()
 {
 	// 7-------  mm
 	// -6------  not used
-	// --5-----  8r
+	// --5-----  8r (in text mode, 8 pixel height line instead of 9?)
-	// ---4----  8lp
+	// ---4----  blp
 	// ----3---  grph
 	// -----2--  not used
 	// ------1-  rev
@@ -225,11 +446,33 @@ uint8_t pn8800fxb_state::video_ctrl_r()
 
 void pn8800fxb_state::video_ctrl_w(uint8_t data)
 {
-	logerror("video_ctrl_w: %02x\n", data);
+	if (0)
+		logerror("video_ctrl_w: %02x\n", data);
 
 	m_video_ctrl = data;
 }
 
+void pn8800fxb_state::video_offset_w(uint8_t data)
+{
+	// 765-----  not used
+	// ---4----  oy
+	// ----3210  ox6 to ox3
+
+	m_video_offset = data;
+}
+
+void pn8800fxb_state::cursor_ctrl_w(uint8_t data)
+{
+	// 7-------  curu
+	// -6------  curl
+	// --5-----  cbkh
+	// ---4----  crev
+	// ----3---  curb
+	// -----210  not used
+
+	m_cursor_ctrl = data;
+}
+
 static const gfx_layout charlayout =
 {
 	8, 8,
@@ -249,29 +492,6 @@ GFXDECODE_END
 //  MACHINE EMULATION
 //**************************************************************************
 
-uint8_t pn8800fxb_state::lo_mem_r(offs_t offset)
-{
-	uint8_t data = 0xff;
-	offset += 0x2000;
-
-	if (offset < 0x6000)
-		data = m_maincpu->space(AS_PROGRAM).read_byte(0x60000 + offset);
-	else
-		data = memregion("maincpu")->base()[offset];
-
-	return data;
-}
-
-void pn8800fxb_state::lo_mem_w(offs_t offset, uint8_t data)
-{
-	offset += 0x2000;
-
-	if (offset < 0x6000)
-		m_maincpu->space(AS_PROGRAM).write_byte(0x60000 + offset, data);
-	else
-		logerror("write 6000-7fff %04x %02x\n", offset, data);
-}
-
 void pn8800fxb_state::mem_change_w(uint8_t data)
 {
 	// 7-------  dua
@@ -280,9 +500,11 @@ void pn8800fxb_state::mem_change_w(uint8_t data)
 	// ------1-  dicsel
 	// -------0  rgex
 
-	logerror("mem_change_w: dua %d ramin %d dicsel %d rgex %d\n", BIT(data, 7), BIT(data, 6), BIT(data, 1), BIT(data, 0));
+	if (data != 0x40)
+		logerror("mem_change_w: dua %d ramin %d dicsel %d rgex %d\n", BIT(data, 7), BIT(data, 6), BIT(data, 1), BIT(data, 0));
 
 	m_mem_change = data;
+	m_lomem_view.select(BIT(data, 6));
 }
 
 void pn8800fxb_state::bank_select_w(uint8_t data)
@@ -290,10 +512,21 @@ void pn8800fxb_state::bank_select_w(uint8_t data)
 	// 7654----  not used
 	// ----3210  bank selection
 
-	logerror("bank_select_w: %02x\n", data);
+	if (0)
+		logerror("bank_select_w: %02x\n", data);
 
 	if (data < 12)
-		m_rombank->set_entry(data ^ 8); // TODO, but works for now
+		m_rombank->set_entry(data & 0x07); // TODO, but works for now
+}
+
+void pn8800fxb_state::int_ack_w(uint8_t data)
+{
+	m_maincpu->set_input_line(INPUT_LINE_IRQ1, CLEAR_LINE);
+}
+
+TIMER_DEVICE_CALLBACK_MEMBER( pn8800fxb_state::int1_timer )
+{
+	m_maincpu->set_input_line(INPUT_LINE_IRQ1, ASSERT_LINE);
 }
 
 void pn8800fxb_state::machine_start()
@@ -308,15 +541,20 @@ void pn8800fxb_state::machine_start()
 	m_rombank->configure_entries(0, 12, memregion("maincpu")->base() + 0x40000, 0x10000);
 
 	// register for save states
+	save_item(NAME(m_key_select));
 	save_pointer(NAME(m_vram), 0x4000);
+	save_item(NAME(m_cursor_addr));
 	save_item(NAME(m_video_addr));
 	save_item(NAME(m_video_ctrl));
+	save_item(NAME(m_video_offset));
+	save_item(NAME(m_cursor_ctrl));
 	save_item(NAME(m_mem_change));
 }
 
 void pn8800fxb_state::machine_reset()
 {
 	m_mem_change = 0x00;
+	m_lomem_view.select(0);
 }
 
 
@@ -330,6 +568,8 @@ void pn8800fxb_state::pn8800fxb(machine_config &config)
 	m_maincpu->set_addrmap(AS_PROGRAM, &pn8800fxb_state::mem_map);
 	m_maincpu->set_addrmap(AS_IO, &pn8800fxb_state::io_map);
 
+	TIMER(config, "1khz").configure_periodic(FUNC(pn8800fxb_state::int1_timer), attotime::from_hz(1000));
+
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_LCD));
 	screen.set_size(640, 200);
 	screen.set_visarea_full();