i8244: use device rom instead of lookup table for character set [Kevin Horton]

src/devices/video/ef9340_1.cpp

@@ -2,8 +2,6 @@
 // copyright-holders:Wilbert Pol
 /***************************************************************************
 
-    ef9340_1.h
-
     Thomson EF9340 + EF9341 teletext graphics chips with 1KB external
     character ram.
 

src/devices/video/ef9340_1.h

@@ -2,8 +2,6 @@
 // copyright-holders:Wilbert Pol
 /***************************************************************************
 
-    ef9340_1.h
-
     Thomson EF9340 + EF9341 teletext graphics chips with 1KB external
     character ram.
 

src/devices/video/i8244.cpp

@@ -5,8 +5,6 @@
 Intel 8244 (NTSC)/8245 (PAL) Graphics and sound chip
 
 TODO:
-- make the character rom external, but first verify it is correct (the table
-  below has 0x3f characters, it is missing 8 bytes)
 - NTSC has 263 scanlines, PAL has 313 scanlines, a quick fix will probably
   cause small regressions here and there
 - PAL has 228 clocks per line (so, 456 half clocks)
@@ -25,76 +23,6 @@ DEFINE_DEVICE_TYPE(I8244, i8244_device, "i8244", "Intel 8244")
 DEFINE_DEVICE_TYPE(I8245, i8245_device, "i8245", "Intel 8245")
 
 
-// Kevtris verified that the data below matches a dump
-// taken from a real chip.
-static const uint8_t c_shape[0x40 * 8] =
-{
-	0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00, // 0
-	0x18,0x38,0x18,0x18,0x18,0x18,0x3C,0x00,
-	0x3C,0x66,0x0C,0x18,0x30,0x60,0x7E,0x00,
-	0x7C,0xC6,0x06,0x3C,0x06,0xC6,0x7C,0x00,
-	0xCC,0xCC,0xCC,0xFE,0x0C,0x0C,0x0C,0x00,
-	0xFE,0xC0,0xC0,0x7C,0x06,0xC6,0x7C,0x00,
-	0x7C,0xC6,0xC0,0xFC,0xC6,0xC6,0x7C,0x00,
-	0xFE,0x06,0x0C,0x18,0x30,0x60,0xC0,0x00,
-	0x7C,0xC6,0xC6,0x7C,0xC6,0xC6,0x7C,0x00,
-	0x7C,0xC6,0xC6,0x7E,0x06,0xC6,0x7C,0x00,
-	0x00,0x18,0x18,0x00,0x18,0x18,0x00,0x00,
-	0x18,0x7E,0x58,0x7E,0x1A,0x7E,0x18,0x00,
-	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-	0x3C,0x66,0x0C,0x18,0x18,0x00,0x18,0x00,
-	0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0xFE,0x00,
-	0xFC,0xC6,0xC6,0xFC,0xC0,0xC0,0xC0,0x00,
-	0x00,0x18,0x18,0x7E,0x18,0x18,0x00,0x00,
-	0xC6,0xC6,0xC6,0xD6,0xFE,0xEE,0xC6,0x00,
-	0xFE,0xC0,0xC0,0xF8,0xC0,0xC0,0xFE,0x00,
-	0xFC,0xC6,0xC6,0xFC,0xD8,0xCC,0xC6,0x00,
-	0x7E,0x18,0x18,0x18,0x18,0x18,0x18,0x00,
-	0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,
-	0x3C,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,
-	0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,
-	0x7C,0xC6,0xC6,0xC6,0xDE,0xCC,0x76,0x00,
-	0x7C,0xC6,0xC0,0x7C,0x06,0xC6,0x7C,0x00,
-	0xFC,0xC6,0xC6,0xC6,0xC6,0xC6,0xFC,0x00,
-	0xFE,0xC0,0xC0,0xF8,0xC0,0xC0,0xC0,0x00,
-	0x7C,0xC6,0xC0,0xC0,0xCE,0xC6,0x7E,0x00,
-	0xC6,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0x00,
-	0x06,0x06,0x06,0x06,0x06,0xC6,0x7C,0x00,
-	0xC6,0xCC,0xD8,0xF0,0xD8,0xCC,0xC6,0x00,
-	0x38,0x6C,0xC6,0xC6,0xFE,0xC6,0xC6,0x00,
-	0x7E,0x06,0x0C,0x18,0x30,0x60,0x7E,0x00,
-	0xC6,0xC6,0x6C,0x38,0x6C,0xC6,0xC6,0x00,
-	0x7C,0xC6,0xC0,0xC0,0xC0,0xC6,0x7C,0x00,
-	0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x00,
-	0xFC,0xC6,0xC6,0xFC,0xC6,0xC6,0xFC,0x00,
-	0xC6,0xEE,0xFE,0xD6,0xC6,0xC6,0xC6,0x00,
-	0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00,
-	0x00,0x00,0x00,0x7E,0x00,0x00,0x00,0x00,
-	0x00,0x66,0x3C,0x18,0x3C,0x66,0x00,0x00,
-	0x00,0x18,0x00,0x7E,0x00,0x18,0x00,0x00,
-	0x00,0x00,0x7E,0x00,0x7E,0x00,0x00,0x00,
-	0x66,0x66,0x66,0x3C,0x18,0x18,0x18,0x00,
-	0xC6,0xE6,0xF6,0xFE,0xDE,0xCE,0xC6,0x00,
-	0x03,0x06,0x0C,0x18,0x30,0x60,0xC0,0x00,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,
-	0xCE,0xDB,0xDB,0xDB,0xDB,0xDB,0xCE,0x00,
-	0x00,0x00,0x3C,0x7E,0x7E,0x7E,0x3C,0x00,
-	0x1C,0x1C,0x18,0x1E,0x18,0x18,0x1C,0x00,
-	0x1C,0x1C,0x18,0x1E,0x18,0x34,0x26,0x00,
-	0x38,0x38,0x18,0x78,0x18,0x2C,0x64,0x00,
-	0x38,0x38,0x18,0x78,0x18,0x18,0x38,0x00,
-	0x00,0x18,0x0C,0xFE,0x0C,0x18,0x00,0x00,
-	0x18,0x3C,0x7E,0xFF,0xFF,0x18,0x18,0x00,
-	0x03,0x07,0x0F,0x1F,0x3F,0x7F,0xFF,0x00,
-	0xC0,0xE0,0xF0,0xF8,0xFC,0xFE,0xFF,0x00,
-	0x38,0x38,0x12,0xFE,0xB8,0x28,0x6C,0x00,
-	0xC0,0x60,0x30,0x18,0x0C,0x06,0x03,0x00,
-	0x00,0x00,0x0C,0x08,0x08,0x7F,0x3E,0x00,
-	0x00,0x03,0x63,0xFF,0xFF,0x18,0x08,0x00,
-	0x00,0x00,0x00,0x10,0x38,0xFF,0x7E,0x00
-};
-
-
 // Background and grid information is stored in RGB format
 // while the character and sprite colors are stored in BGR
 // format.
@@ -120,6 +48,7 @@ i8244_device::i8244_device(const machine_config &mconfig, device_type type, cons
 	, device_video_interface(mconfig, *this)
 	, m_irq_func(*this)
 	, m_postprocess_func(*this)
+	, m_charset(*this, "cgrom")
 	, m_start_vpos(START_Y)
 	, m_start_vblank(START_Y + SCREEN_HEIGHT)
 	, m_screen_lines(lines)
@@ -133,6 +62,22 @@ i8245_device::i8245_device(const machine_config &mconfig, const char *tag, devic
 }
 
 
+//-------------------------------------------------
+//  internal character set rom
+//-------------------------------------------------
+
+ROM_START( i8244 )
+	ROM_REGION( 0x200, "cgrom", 0 )
+	ROM_LOAD( "charset_i8244.bin", 0x0000, 0x0200, CRC(b46a3f31) SHA1(415382715455b47b69401b3d60bd8f0036dd7fef) )
+ROM_END
+
+
+const tiny_rom_entry *i8244_device::device_rom_region() const
+{
+	return ROM_NAME( i8244 );
+}
+
+
 //-------------------------------------------------
 //  device_config_complete - perform any
 //  operations now that the configuration is
@@ -525,7 +470,7 @@ void i8244_device::render_scanline(int vpos)
 				{
 					uint16_t color = 8 + bgr2rgb[ ( ( m_vdc.s.foreground[i].color >> 1 ) & 0x07 ) ];
 					int    offset = ( m_vdc.s.foreground[i].ptr | ( ( m_vdc.s.foreground[i].color & 0x01 ) << 8 ) ) + ( y >> 1 ) + ( ( scanline - y ) >> 1 );
-					uint8_t  chr = c_shape[ offset & 0x1FF ];
+					uint8_t  chr = m_charset[ offset & 0x1FF ];
 					int    x = m_vdc.s.foreground[i].x;
 
 					for ( uint8_t m = 0x80; m > 0; m >>= 1, x++ )
@@ -572,7 +517,7 @@ void i8244_device::render_scanline(int vpos)
 						{
 							uint16_t color = 8 + bgr2rgb[ ( ( m_vdc.s.quad[i].single[j].color >> 1 ) & 0x07 ) ];
 							int offset = ( m_vdc.s.quad[i].single[j].ptr | ( ( m_vdc.s.quad[i].single[j].color & 0x01 ) << 8 ) ) + ( y >> 1 ) + ( ( scanline - y ) >> 1 );
-							uint8_t chr = c_shape[ offset & 0x1FF ];
+							uint8_t chr = m_charset[ offset & 0x1FF ];
 
 							for ( uint8_t m = 0x80; m > 0; m >>= 1, x++ )
 							{

src/devices/video/i8244.h

@@ -92,6 +92,7 @@ protected:
 	virtual void device_start() override;
 	virtual void device_reset() override;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
+	virtual const tiny_rom_entry *device_rom_region() const override;
 
 	// device_sound_interface overrides
 	virtual void sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) override;
@@ -112,6 +113,8 @@ protected:
 	devcb_write_line m_irq_func;
 	devcb_write16 m_postprocess_func;
 
+	required_region_ptr<uint8_t> m_charset;
+
 	bitmap_ind16 m_tmp_bitmap;
 	emu_timer *m_line_timer;
 	emu_timer *m_hblank_timer;