From c2622359f9ca7a4bca91fd673ad2d3b84dc508f1 Mon Sep 17 00:00:00 2001
From: Ralf Grillenberger <h-a-l-9000@users.sourceforge.net>
Date: Fri, 1 Oct 2010 19:39:14 +0000
Subject: [PATCH] - implement Tandy special 4-color palette handling - remove
 3d8/3d9 from PCJr mode (PCJr didn't have it) - update INT10 palette functions
 accordingly - add a level of indirection to Tandy and PCjr palette deconding
 to fix video recording with on-screen palette changes - enable line-by-line
 emulation for Tandy too - machine-specific implementation of the color when
 display is disabled (vgaonly too) - enable the light pen stub on all machines
 that it is documented for - mask off a bank-selection bit that is not used
 under a specific circumstance

Fixes Alley Cat palette on PCJr, Gauntlet, Ghostbusters, Pirates! on Tandy, Video recording on Tandy/PCJr where the palette is changed on-screen


Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3647
---
 src/hardware/vga_draw.cpp  |  91 ++++++++++---
 src/hardware/vga_other.cpp | 268 +++++++++++++++++++++++--------------
 src/ints/int10.cpp         |   3 +-
 src/ints/int10_modes.cpp   |   9 +-
 src/ints/int10_pal.cpp     |  86 ++++++++++--
 5 files changed, 327 insertions(+), 130 deletions(-)

diff --git a/src/hardware/vga_draw.cpp b/src/hardware/vga_draw.cpp
index c5330421..494a2b34 100644
--- a/src/hardware/vga_draw.cpp
+++ b/src/hardware/vga_draw.cpp
@@ -118,30 +118,30 @@ static Bit8u * VGA_Draw_CGA16_Line(Bitu vidstart, Bitu line) {
 
 static Bit8u * VGA_Draw_4BPP_Line(Bitu vidstart, Bitu line) {
 	const Bit8u *base = vga.tandy.draw_base + ((line & vga.tandy.line_mask) << vga.tandy.line_shift);
-	Bit32u * draw=(Bit32u *)TempLine;
-	for (Bitu x=0;x<vga.draw.blocks;x++) {
-		Bitu val1 = base[vidstart & vga.tandy.addr_mask];
-		++vidstart;
-		Bitu val2 = base[vidstart & vga.tandy.addr_mask];
-		++vidstart;
-		*draw++=(val1 & 0x0f) << 8  |
-				(val1 & 0xf0) >> 4  |
-				(val2 & 0x0f) << 24 |
-				(val2 & 0xf0) << 12;
+	Bit8u* draw=TempLine;
+	Bitu end = vga.draw.blocks*2;
+	while(end) {
+		Bit8u byte = base[vidstart & vga.tandy.addr_mask];
+		*draw++=vga.attr.palette[byte >> 4];
+		*draw++=vga.attr.palette[byte & 0x0f];
+		vidstart++;
+		end--;
 	}
 	return TempLine;
 }
 
 static Bit8u * VGA_Draw_4BPP_Line_Double(Bitu vidstart, Bitu line) {
 	const Bit8u *base = vga.tandy.draw_base + ((line & vga.tandy.line_mask) << vga.tandy.line_shift);
-	Bit32u * draw=(Bit32u *)TempLine;
-	for (Bitu x=0;x<vga.draw.blocks;x++) {
-		Bitu val = base[vidstart & vga.tandy.addr_mask];
-		++vidstart;
-		*draw++=(val & 0xf0) >> 4  |
-				(val & 0xf0) << 4  |
-				(val & 0x0f) << 16 |
-				(val & 0x0f) << 24;
+	Bit8u* draw=TempLine;
+	Bitu end = vga.draw.blocks;
+	while(end) {
+		Bit8u byte = base[vidstart & vga.tandy.addr_mask];
+		Bit8u data = vga.attr.palette[byte >> 4];
+		*draw++ = data; *draw++ = data;
+		data = vga.attr.palette[byte & 0x0f];
+		*draw++ = data; *draw++ = data;
+		vidstart++;
+		end--;
 	}
 	return TempLine;
 }
@@ -589,10 +589,60 @@ static void VGA_ProcessSplit() {
 	vga.draw.address_line=0;
 }
 
+static Bit8u bg_color_index = 0; // screen-off black index
 static void VGA_DrawSingleLine(Bitu /*blah*/) {
 	if (GCC_UNLIKELY(vga.attr.disabled)) {
-		// draw blanked line (DoWhackaDo, Alien Carnage, TV sports Football)
-		memset(TempLine, 0, sizeof(TempLine));
+		switch(machine) {
+		case MCH_PCJR:
+			// Displays the border color when screen is disabled
+			bg_color_index = vga.tandy.border_color;
+			break;
+		case MCH_TANDY:
+			// Either the PCJr way or the CGA way
+			if (vga.tandy.gfx_control& 0x4) { 
+				bg_color_index = vga.tandy.border_color;
+			} else if (vga.mode==M_TANDY4) 
+				bg_color_index = vga.attr.palette[0];
+			else bg_color_index = 0;
+			break;
+		case MCH_CGA:
+			// the background color
+			bg_color_index = vga.attr.overscan_color;
+			break;
+		case MCH_EGA:
+		case MCH_VGA:
+			// DoWhackaDo, Alien Carnage, TV sports Football
+			// when disabled by attribute index bit 5:
+			//  ET3000, ET4000, Paradise display the border color
+			//  S3 displays the content of the currently selected attribute register
+			// when disabled by sequencer the screen is black "257th color"
+			
+			// the DAC table may not match the bits of the overscan register
+			// so use black for this case too...
+			//if (vga.attr.disabled& 2) {
+			if (vga.dac.xlat16[bg_color_index] != 0) {
+				for(Bitu i = 0; i < 256; i++)
+					if (vga.dac.xlat16[i] == 0) {
+						bg_color_index = i;
+						break;
+					}
+			}
+			//} else 
+            //    bg_color_index = vga.attr.overscan_color;
+			break;
+		default:
+			bg_color_index = 0;
+			break;
+		}
+		if (vga.draw.bpp==8) {
+			memset(TempLine, bg_color_index, sizeof(TempLine));
+		} else if (vga.draw.bpp==16) {
+			Bit16u* wptr = (Bit16u*) TempLine;
+			Bit16u value = vga.dac.xlat16[bg_color_index];
+			for (Bitu i = 0; i < sizeof(TempLine)/2; i++) {
+				wptr[i] = value;
+			}
+		}
 		RENDER_DrawLine(TempLine);
 	} else {
 		Bit8u * data=VGA_DrawLine( vga.draw.address, vga.draw.address_line );	
@@ -966,6 +1016,7 @@ void VGA_SetupDrawing(Bitu /*val*/) {
 	switch (machine) {
 	case MCH_CGA:
 	case MCH_PCJR:
+	case MCH_TANDY:
 		vga.draw.mode = LINE;
 		break;
 	case MCH_EGA:
diff --git a/src/hardware/vga_other.cpp b/src/hardware/vga_other.cpp
index 7fd18293..c6cd613f 100644
--- a/src/hardware/vga_other.cpp
+++ b/src/hardware/vga_other.cpp
@@ -153,6 +153,27 @@ static Bitu read_crtc_data_other(Bitu /*port*/,Bitu /*iolen*/) {
 	return (Bitu)(~0);
 }
 
+static void write_lightpen(Bitu port,Bitu val,Bitu) {
+	switch (port) {
+	case 0x3db:	// Clear lightpen latch
+		vga.other.lightpen_triggered = false;
+		break;
+	case 0x3dc:	// Preset lightpen latch
+		if (!vga.other.lightpen_triggered) {
+			vga.other.lightpen_triggered = true; // TODO: this shows at port 3ba/3da bit 1
+			
+			double timeInFrame = PIC_FullIndex()-vga.draw.delay.framestart;
+			double timeInLine = fmod(timeInFrame,vga.draw.delay.htotal);
+			Bitu current_scanline = (Bitu)(timeInFrame / vga.draw.delay.htotal);
+			
+			vga.other.lightpen = (Bit16u)((vga.draw.address_add/2) * (current_scanline/2));
+			vga.other.lightpen += (Bit16u)((timeInLine / vga.draw.delay.hdend) *
+				((float)(vga.draw.address_add/2)));
+		}
+		break;
+	}
+}
+
 static double hue_offset = 0.0;
 static Bit8u cga16_val = 0;
 static void update_cga16_color(void);
@@ -235,56 +256,139 @@ static void DecreaseHue(bool pressed) {
 	LOG_MSG("Hue at %f",hue_offset); 
 }
 
-static void write_color_select(Bit8u val) {
+static void write_cga_color_select(Bitu val) {
 	vga.tandy.color_select=val;
-	switch (vga.mode) {
+	switch(vga.mode) {
+	case  M_TANDY4: {
+		Bit8u base = (val & 0x10) ? 0x08 : 0;
+		Bit8u bg = val & 0xf;
+		if (vga.tandy.mode_control & 0x4)	// cyan red white
+			VGA_SetCGA4Table(bg, 3+base, 4+base, 7+base);
+		else if (val & 0x20)				// cyan magenta white
+			VGA_SetCGA4Table(bg, 3+base, 5+base, 7+base);
+		else								// green red brown
+			VGA_SetCGA4Table(bg, 2+base, 4+base, 6+base);
+		vga.tandy.border_color = bg;
+		vga.attr.overscan_color = bg;
+		break;
+	}
 	case M_TANDY2:
 		VGA_SetCGA2Table(0,val & 0xf);
-		break;
-	case M_TANDY4:
-		{
-			if ((machine==MCH_TANDY && (vga.tandy.gfx_control & 0x8)) ||
-				(machine==MCH_PCJR && (vga.tandy.mode_control==0x0b))) {
-				VGA_SetCGA4Table(0,1,2,3);
-				return;
-			}
-			Bit8u base=(val & 0x10) ? 0x08 : 0;
-			/* Check for BW Mode */
-			if (vga.tandy.mode_control & 0x4) {
-				VGA_SetCGA4Table(val & 0xf,3+base,4+base,7+base);
-			} else {
-				if (val & 0x20) VGA_SetCGA4Table(val & 0xf,3+base,5+base,7+base);
-				else VGA_SetCGA4Table(val & 0xf,2+base,4+base,6+base);
-			}
-		}
+		vga.attr.overscan_color = 0;
 		break;
 	case M_CGA16:
 		cga16_color_select(val);
 		break;
 	case M_TEXT:
-	case M_TANDY16:
+		vga.tandy.border_color = val & 0xf;
+		vga.attr.overscan_color = 0;
 		break;
 	}
 }
 
-static void TANDY_FindMode(void) {
-	if (vga.tandy.mode_control & 0x2) {
-		if (vga.tandy.gfx_control & 0x10) 
-			VGA_SetMode(M_TANDY16);
-		else if (vga.tandy.gfx_control & 0x08) 
-			VGA_SetMode(M_TANDY4);
-		else if (vga.tandy.mode_control & 0x10)
-			VGA_SetMode(M_TANDY2);
-		else
-			VGA_SetMode(M_TANDY4);
-		write_color_select(vga.tandy.color_select);
+static void write_cga(Bitu port,Bitu val,Bitu /*iolen*/) {
+	switch (port) {
+	case 0x3d8:
+		vga.tandy.mode_control=(Bit8u)val;
+		vga.attr.disabled = (val&0x8)? 0: 1; 
+		if (vga.tandy.mode_control & 0x2) {		// graphics mode
+			if (vga.tandy.mode_control & 0x10) {// highres mode
+				if (!(val & 0x4)) {				// burst on
+					VGA_SetMode(M_CGA16);		// composite ntsc 160x200 16 color mode
+				} else {
+					VGA_SetMode(M_TANDY2);
+				}
+			} else VGA_SetMode(M_TANDY4);		// lowres mode
+
+			write_cga_color_select(vga.tandy.color_select);
+		} else {
+			VGA_SetMode(M_TANDY_TEXT);
+		}
+		VGA_SetBlinking(val & 0x20);
+		break;
+	case 0x3d9: // color select
+		write_cga_color_select(val);
+		break;
+	}
+}
+
+static void tandy_update_palette() {
+	// TODO mask off bits if needed
+	if (machine == MCH_TANDY) {
+		switch (vga.mode) {
+		case M_TANDY2:
+			VGA_SetCGA2Table(vga.attr.palette[0],
+				//vga.attr.palette[vga.tandy.color_select&0xf]);
+				vga.attr.palette[0xf]);
+			//VGA_SetCGA2Table(vga.attr.palette[0xf],vga.attr.palette[0]);
+			break;
+		case M_TANDY4:
+			if (vga.tandy.gfx_control & 0x8) {
+				// 4-color high resolution - might be an idea to introduce M_TANDY4H
+				VGA_SetCGA4Table( // function sets both medium and highres 4color tables
+					vga.attr.palette[0], vga.attr.palette[1],
+					vga.attr.palette[2], vga.attr.palette[3]);
+			} else {
+				Bit8u color_set = 0;
+				Bit8u r_mask = 0xf;
+				if (vga.tandy.color_select & 0x10) color_set |= 8; // intensity
+				if (vga.tandy.color_select & 0x20) color_set |= 1; // Cyan Mag. White
+				if (vga.tandy.mode_control & 0x04) {			// Cyan Red White
+					color_set |= 1; 
+					r_mask &= ~1;
+				}
+				VGA_SetCGA4Table(
+					vga.attr.palette[0],
+					vga.attr.palette[(2|color_set)& vga.tandy.palette_mask],
+					vga.attr.palette[(4|(color_set& r_mask))& vga.tandy.palette_mask],
+					vga.attr.palette[(6|color_set)& vga.tandy.palette_mask]);
+			}
+			break;
+		default:
+			break;
+		}
 	} else {
-		VGA_SetMode(M_TANDY_TEXT);
+		// PCJr
+		switch (vga.mode) {
+		case M_TANDY2:
+			VGA_SetCGA2Table(vga.attr.palette[0],vga.attr.palette[1]);
+			break;
+		case M_TANDY4:
+			VGA_SetCGA4Table(
+				vga.attr.palette[0], vga.attr.palette[1],
+				vga.attr.palette[2], vga.attr.palette[3]);
+			break;
+		default:
+			break;
+		}
 	}
 }
 
 void VGA_SetModeNow(VGAModes mode);
 
+static void TANDY_FindMode(void) {
+	if (vga.tandy.mode_control & 0x2) {
+		if (vga.tandy.gfx_control & 0x10) {
+			if (vga.mode==M_TANDY4) {
+				VGA_SetModeNow(M_TANDY16);
+			} else VGA_SetMode(M_TANDY16);
+		}
+		else if (vga.tandy.gfx_control & 0x08) {
+			VGA_SetMode(M_TANDY4);
+		}
+		else if (vga.tandy.mode_control & 0x10)
+			VGA_SetMode(M_TANDY2);
+		else {
+			if (vga.mode==M_TANDY16) {
+				VGA_SetModeNow(M_TANDY4);
+			} else VGA_SetMode(M_TANDY4);
+		}
+		tandy_update_palette();
+	} else {
+		VGA_SetMode(M_TANDY_TEXT);
+	}
+}
+
 static void PCJr_FindMode(void) {
 	if (vga.tandy.mode_control & 0x2) {
 		if (vga.tandy.mode_control & 0x10) {
@@ -299,7 +403,6 @@ static void PCJr_FindMode(void) {
 			if (vga.mode==M_TANDY16) VGA_SetModeNow(M_TANDY4);
 			else VGA_SetMode(M_TANDY4);
 		}
-		write_color_select(vga.tandy.color_select);
 	} else {
 		VGA_SetMode(M_TANDY_TEXT);
 	}
@@ -327,11 +430,16 @@ static void write_tandy_reg(Bit8u val) {
 			vga.tandy.mode_control=val;
 			VGA_SetBlinking(val & 0x20);
 			PCJr_FindMode();
-			vga.attr.disabled = (val&0x8)? 0: 1;
+			if (val&0x8) vga.attr.disabled &= ~1;
+			else vga.attr.disabled |= 1;
 		} else {
 			LOG(LOG_VGAMISC,LOG_NORMAL)("Unhandled Write %2X to tandy reg %X",val,vga.tandy.reg_index);
 		}
 		break;
+	case 0x1:	/* Palette mask */
+		vga.tandy.palette_mask = val;
+		tandy_update_palette();
+		break;
 	case 0x2:	/* Border color */
 		vga.tandy.border_color=val;
 		break;
@@ -348,45 +456,12 @@ static void write_tandy_reg(Bit8u val) {
 		TandyCheckLineMask();
 		VGA_SetupHandlers();
 		break;
-	case 0x8:	/* Monitor mode seletion */
-		//Bit 1 select mode e, for 640x200x16, some double clocking thing?
-		//Bit 4 select 350 line mode for hercules emulation
-		LOG(LOG_VGAMISC,LOG_NORMAL)("Write %2X to tandy monitor mode",val );
-		break;
-	/* palette colors */
-	case 0x10: case 0x11: case 0x12: case 0x13:
-	case 0x14: case 0x15: case 0x16: case 0x17:
-	case 0x18: case 0x19: case 0x1a: case 0x1b:
-	case 0x1c: case 0x1d: case 0x1e: case 0x1f:
-		VGA_ATTR_SetPalette(vga.tandy.reg_index-0x10,val & 0xf);
-		break;
-	default:		
-		LOG(LOG_VGAMISC,LOG_NORMAL)("Unhandled Write %2X to tandy reg %X",val,vga.tandy.reg_index);
-	}
-}
-
-static void write_cga(Bitu port,Bitu val,Bitu /*iolen*/) {
-	switch (port) {
-	case 0x3d8:
-		vga.tandy.mode_control=(Bit8u)val;
-		vga.attr.disabled = (val&0x8)? 0: 1; 
-		if (vga.tandy.mode_control & 0x2) {
-			if (vga.tandy.mode_control & 0x10) {
-				if (!(val & 0x4) && machine==MCH_CGA) {
-					VGA_SetMode(M_CGA16);		//Video burst 16 160x200 color mode
-				} else {
-					VGA_SetMode(M_TANDY2);
-				}
-			} else VGA_SetMode(M_TANDY4);
-			write_color_select(vga.tandy.color_select);
-		} else {
-			VGA_SetMode(M_TANDY_TEXT);
-		}
-		VGA_SetBlinking(val & 0x20);
-		break;
-	case 0x3d9:
-		write_color_select((Bit8u)val);
-		break;
+	default:
+		if ((vga.tandy.reg_index & 0xf0) == 0x10) { // color palette
+			vga.attr.palette[vga.tandy.reg_index-0x10] = val&0xf;
+			tandy_update_palette();
+		} else
+			LOG(LOG_VGAMISC,LOG_NORMAL)("Unhandled Write %2X to tandy reg %X",val,vga.tandy.reg_index);
 	}
 }
 
@@ -394,40 +469,32 @@ static void write_tandy(Bitu port,Bitu val,Bitu /*iolen*/) {
 	switch (port) {
 	case 0x3d8:
 		vga.tandy.mode_control=(Bit8u)val;
+		if (val&0x8) vga.attr.disabled &= ~1;
+		else vga.attr.disabled |= 1;
 		TandyCheckLineMask();
 		VGA_SetBlinking(val & 0x20);
 		TANDY_FindMode();
 		break;
 	case 0x3d9:
-		write_color_select((Bit8u)val);
+		vga.tandy.color_select=val;
+		if (vga.mode==M_TANDY2) vga.attr.palette[0xf] = vga.tandy.color_select&0xf;
+		else vga.attr.palette[0] = vga.tandy.color_select&0xf; // Pirates!
+		tandy_update_palette();
 		break;
 	case 0x3da:
 		vga.tandy.reg_index=(Bit8u)val;
-		break;
-	case 0x3db:	// Clear lightpen latch
-		vga.other.lightpen_triggered = false;
-		break;
-	case 0x3dc:	// Preset lightpen latch
-		if (!vga.other.lightpen_triggered) {
-			vga.other.lightpen_triggered = true; // TODO: this shows at port 3ba/3da bit 1
-			
-			double timeInFrame = PIC_FullIndex()-vga.draw.delay.framestart;
-			double timeInLine = fmod(timeInFrame,vga.draw.delay.htotal);
-			Bitu current_scanline = (Bitu)(timeInFrame / vga.draw.delay.htotal);
-			
-			vga.other.lightpen = (Bit16u)((vga.draw.address_add/2) * (current_scanline/2));
-			vga.other.lightpen += (Bit16u)((timeInLine / vga.draw.delay.hdend) *
-				((float)(vga.draw.address_add/2)));
-		}
+		//if (val&0x10) vga.attr.disabled |= 2;
+		//else vga.attr.disabled &= ~2;
 		break;
 //	case 0x3dd:	//Extended ram page address register:
-		break;
+//		break;
 	case 0x3de:
 		write_tandy_reg((Bit8u)val);
 		break;
 	case 0x3df:
 		vga.tandy.line_mask = (Bit8u)(val >> 6);
 		vga.tandy.draw_bank = val & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
+		if(vga.tandy.line_mask==3) vga.tandy.draw_bank &= ~1; // LSB unused in 32k modes
 		vga.tandy.mem_bank = (val >> 3) & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
 		TandyCheckLineMask();
 		VGA_SetupHandlers();
@@ -437,12 +504,14 @@ static void write_tandy(Bitu port,Bitu val,Bitu /*iolen*/) {
 
 static void write_pcjr(Bitu port,Bitu val,Bitu /*iolen*/) {
 	switch (port) {
-	case 0x3d9:
-		write_color_select((Bit8u)val);
-		break;
 	case 0x3da:
 		if (vga.tandy.pcjr_flipflop) write_tandy_reg((Bit8u)val);
-		else vga.tandy.reg_index=(Bit8u)val;
+		else {
+			vga.tandy.reg_index=(Bit8u)val;
+			if (vga.tandy.reg_index & 0x10)
+				vga.attr.disabled |= 2;
+			else vga.attr.disabled &= ~2;
+		}
 		vga.tandy.pcjr_flipflop=!vga.tandy.pcjr_flipflop;
 		break;
 	case 0x3df:
@@ -577,6 +646,10 @@ void VGA_SetupOther(void) {
 		for (i=0;i<256;i++)	memcpy(&vga.draw.font[i*32],&int10_font_08[i*8],8);
 		vga.draw.font_tables[0]=vga.draw.font_tables[1]=vga.draw.font;
 	}
+	if (machine==MCH_CGA || IS_TANDY_ARCH || machine==MCH_HERC) {
+		IO_RegisterWriteHandler(0x3db,write_lightpen,IO_MB);
+		IO_RegisterWriteHandler(0x3dc,write_lightpen,IO_MB);
+	}
 	if (machine==MCH_HERC) {
 		extern Bit8u int10_font_14[256 * 14];
 		for (i=0;i<256;i++)	memcpy(&vga.draw.font[i*32],&int10_font_14[i*14],14);
@@ -586,8 +659,6 @@ void VGA_SetupOther(void) {
 	if (machine==MCH_CGA) {
 		IO_RegisterWriteHandler(0x3d8,write_cga,IO_MB);
 		IO_RegisterWriteHandler(0x3d9,write_cga,IO_MB);
-		IO_RegisterWriteHandler(0x3db,write_tandy,IO_MB);
-		IO_RegisterWriteHandler(0x3dc,write_tandy,IO_MB);
 		MAPPER_AddHandler(IncreaseHue,MK_f11,MMOD2,"inchue","Inc Hue");
 		MAPPER_AddHandler(DecreaseHue,MK_f11,0,"dechue","Dec Hue");
 	}
@@ -595,14 +666,13 @@ void VGA_SetupOther(void) {
 		write_tandy( 0x3df, 0x0, 0 );
 		IO_RegisterWriteHandler(0x3d8,write_tandy,IO_MB);
 		IO_RegisterWriteHandler(0x3d9,write_tandy,IO_MB);
+		IO_RegisterWriteHandler(0x3da,write_tandy,IO_MB);
 		IO_RegisterWriteHandler(0x3de,write_tandy,IO_MB);
 		IO_RegisterWriteHandler(0x3df,write_tandy,IO_MB);
-		IO_RegisterWriteHandler(0x3da,write_tandy,IO_MB);
 	}
 	if (machine==MCH_PCJR) {
 		//write_pcjr will setup base address
 		write_pcjr( 0x3df, 0x7 | (0x7 << 3), 0 );
-		IO_RegisterWriteHandler(0x3d9,write_pcjr,IO_MB);
 		IO_RegisterWriteHandler(0x3da,write_pcjr,IO_MB);
 		IO_RegisterWriteHandler(0x3df,write_pcjr,IO_MB);
 	}
diff --git a/src/ints/int10.cpp b/src/ints/int10.cpp
index dd86ad85..cc367ea3 100644
--- a/src/ints/int10.cpp
+++ b/src/ints/int10.cpp
@@ -140,7 +140,8 @@ static Bitu INT10_Handler(void) {
 		reg_ah=(Bit8u)real_readw(BIOSMEM_SEG,BIOSMEM_NB_COLS);
 		break;					
 	case 0x10:								/* Palette functions */
-		if ((machine==MCH_CGA) || ((!IS_VGA_ARCH) && (reg_al>0x03))) break;
+		if (!IS_EGAVGA_ARCH && (reg_al>0x02)) break;
+		else if (!IS_VGA_ARCH && (reg_al>0x03)) break;
 		switch (reg_al) {
 		case 0x00:							/* SET SINGLE PALETTE REGISTER */
 			INT10_SetSinglePaletteRegister(reg_bl,reg_bh);
diff --git a/src/ints/int10_modes.cpp b/src/ints/int10_modes.cpp
index 54fdaccb..d3d7099d 100644
--- a/src/ints/int10_modes.cpp
+++ b/src/ints/int10_modes.cpp
@@ -246,6 +246,7 @@ VideoModeBlock ModeList_OTHER[]={
 { 0x008  ,M_TANDY16,160 ,200 ,20 ,25 ,8 ,8  ,8 ,0xB8000 ,0x2000 ,56  ,127 ,40 ,100 ,0   },
 { 0x009  ,M_TANDY16,320 ,200 ,40 ,25 ,8 ,8  ,8 ,0xB8000 ,0x2000 ,113 ,63  ,80 ,50  ,0   },
 { 0x00A  ,M_CGA4   ,640 ,200 ,80 ,25 ,8 ,8  ,8 ,0xB8000 ,0x2000 ,113 ,63  ,80 ,50  ,0   },
+//{ 0x00E  ,M_TANDY16,640 ,200 ,80 ,25 ,8 ,8  ,8 ,0xA0000 ,0x10000 ,113 ,256 ,80 ,200 ,0   },
 {0xFFFF  ,M_ERROR  ,0   ,0   ,0  ,0  ,0 ,0  ,0 ,0x00000 ,0x0000 ,0   ,0   ,0  ,0   ,0 	},
 };
 
@@ -547,6 +548,11 @@ bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
 		default:
 			IO_WriteB(0x3de,0x0);break;
 		}
+		// write palette
+		for(Bitu i = 0; i < 16; i++) {
+			IO_WriteB(0x3da,i+0x10);
+			IO_WriteB(0x3de,i);
+		}
 		//Clear extended mapping
 		IO_WriteB(0x3da,0x5);
 		IO_WriteB(0x3de,0x0);
@@ -587,8 +593,9 @@ bool INT10_SetVideoMode_OTHER(Bit16u mode,bool clearmem) {
 
 		if (CurMode->mode == 0x6 || CurMode->mode==0xa) color_select=0x3f;
 		else color_select=0x30;
-		IO_WriteB(0x3d9,color_select);
 		real_writeb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL,color_select);
+		INT10_SetColorSelect(1);
+		INT10_SetBackgroundBorder(0);
 		break;
 	}
 
diff --git a/src/ints/int10_pal.cpp b/src/ints/int10_pal.cpp
index 092a647e..4a672c09 100644
--- a/src/ints/int10_pal.cpp
+++ b/src/ints/int10_pal.cpp
@@ -35,9 +35,44 @@ static INLINE void WriteTandyACTL(Bit8u creg,Bit8u val) {
 
 void INT10_SetSinglePaletteRegister(Bit8u reg,Bit8u val) {
 	switch (machine) {
-	case TANDY_ARCH_CASE:
+	case MCH_PCJR:
+		reg&=0xf;
 		IO_Read(VGAREG_TDY_RESET);
 		WriteTandyACTL(reg+0x10,val);
+		IO_Write(0x3da,0x0); // palette back on
+		break;
+	case MCH_TANDY:
+		// TODO waits for vertical retrace
+		switch(vga.mode) {
+		case M_TANDY2:
+			if (reg >= 0x10) break;
+			else if (reg==1) reg = 0x1f;
+			else reg |= 0x10;
+			WriteTandyACTL(reg+0x10,val);
+			break;
+		case M_TANDY4: {
+			if (CurMode->mode!=0x0a) {
+				// Palette values are kept constand by the BIOS.
+				// The four colors are mapped to special palette values by hardware.
+				// 3D8/3D9 registers influence this mapping. We need to figure out
+				// which entry is used for the requested color.
+				if (reg > 3) break;
+				if (reg != 0) { // 0 is assumed to be at 0
+					Bit8u color_select=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL);
+					reg = reg*2+8; // Green Red Brown
+					if (color_select& 0x20) reg++; // Cyan Magenta White
+				}
+				WriteTandyACTL(reg+0x10,val);
+			} 
+			// 4-color high resolution mode 0x0a isn't handled specially
+			else WriteTandyACTL(reg+0x10,val);
+			break;
+		}
+		default:
+			WriteTandyACTL(reg+0x10,val);
+			break;
+		}
+		IO_Write(0x3da,0x0); // palette back on
 		break;
 	case EGAVGA_ARCH_CASE:
 		if (!IS_VGA_ARCH) reg&=0x1f;
@@ -266,14 +301,24 @@ void INT10_SetPelMask(Bit8u mask) {
 
 void INT10_GetPelMask(Bit8u & mask) {
 	mask=IO_Read(VGAREG_PEL_MASK);
-}	
+}
 
 void INT10_SetBackgroundBorder(Bit8u val) {
-	Bit8u temp=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL);
-	temp=(temp & 0xe0) | (val & 0x1f);
-	real_writeb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL,temp);
-	if (machine == MCH_CGA || IS_TANDY_ARCH)
-		IO_Write(0x3d9,temp);
+	Bit8u color_select=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL);
+	color_select=(color_select & 0xe0) | (val & 0x1f);
+	real_writeb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL,color_select);
+	
+	if (machine == MCH_CGA || machine == MCH_TANDY)
+		IO_Write(0x3d9,color_select);
+	else if (machine == MCH_PCJR) {
+		IO_Read(VGAREG_TDY_RESET); // reset the flipflop
+		if (vga.mode!=M_TANDY_TEXT) {
+			IO_Write(VGAREG_TDY_ADDRESS, 0x10);
+			IO_Write(VGAREG_PCJR_DATA, color_select&0xf);
+		}
+		IO_Write(VGAREG_TDY_ADDRESS, 0x2); // border color
+		IO_Write(VGAREG_PCJR_DATA, color_select&0xf);
+	}
 	else if (IS_EGAVGA_ARCH) {
 		val = ((val << 1) & 0x10) | (val & 0x7);
 		/* Aways set the overscan color */
@@ -282,7 +327,7 @@ void INT10_SetBackgroundBorder(Bit8u val) {
 		if (CurMode->mode <= 3)
 			return;
 		INT10_SetSinglePaletteRegister( 0, val );
-		val = (temp & 0x10) | 2 | ((temp & 0x20) >> 5);
+		val = (color_select & 0x10) | 2 | ((color_select & 0x20) >> 5);
 		INT10_SetSinglePaletteRegister( 1, val );
 		val+=2;
 		INT10_SetSinglePaletteRegister( 2, val );
@@ -295,8 +340,31 @@ void INT10_SetColorSelect(Bit8u val) {
 	Bit8u temp=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL);
 	temp=(temp & 0xdf) | ((val & 1) ? 0x20 : 0x0);
 	real_writeb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAL,temp);
-	if (machine == MCH_CGA || IS_TANDY_ARCH)
+	if (machine == MCH_CGA || machine==MCH_TANDY)
 		IO_Write(0x3d9,temp);
+	else if (machine == MCH_PCJR) {
+		switch(vga.mode) {
+		case M_TANDY2:
+			IO_Write(VGAREG_TDY_ADDRESS, 0x11);
+			IO_Write(VGAREG_PCJR_DATA, val&1? 0xf:0);
+			break;
+		case M_TANDY4:
+			for(Bit8u i = 0x11; i < 0x14; i++) {
+				const Bit8u t4_table[] = {0,2,4,6, 0,3,5,0xf};
+				IO_Write(VGAREG_TDY_ADDRESS, i);
+				IO_Write(VGAREG_PCJR_DATA, t4_table[(i-0x10)+(val&1? 4:0)]);
+			}
+			break;
+		default:
+			// 16-color modes: always write the same palette
+			for(Bit8u i = 0x11; i < 0x20; i++) {
+				IO_Write(VGAREG_TDY_ADDRESS, i);
+				IO_Write(VGAREG_PCJR_DATA, i-0x10);
+			}
+			break;
+		}
+		IO_Write(VGAREG_TDY_ADDRESS, 0); // enable palette
+	}
 	else if (IS_EGAVGA_ARCH) {
 		if (CurMode->mode <= 3) //Maybe even skip the total function!
 			return;