diff --git a/include/vga.h b/include/vga.h
index 2674aeee..abd1d296 100644
--- a/include/vga.h
+++ b/include/vga.h
@@ -356,6 +356,7 @@ extern Bit32u ExpandTable[256];
 extern Bit32u FillTable[16];
 extern Bit32u CGA_2_Table[16];
 extern Bit32u CGA_4_Table[256];
+extern Bit32u CGA_4_HiRes_Table[256];
 extern Bit32u CGA_16_Table[256];
 extern Bit32u TXT_Font_Table[16];
 extern Bit32u TXT_FG_Table[16];
diff --git a/src/hardware/vga.cpp b/src/hardware/vga.cpp
index 67fa0ba1..d56735d2 100644
--- a/src/hardware/vga.cpp
+++ b/src/hardware/vga.cpp
@@ -26,6 +26,7 @@ VGA_Type vga;
 
 Bit32u CGA_2_Table[16];
 Bit32u CGA_4_Table[256];
+Bit32u CGA_4_HiRes_Table[256];
 Bit32u CGA_16_Table[256];
 Bit32u TXT_Font_Table[16];
 Bit32u TXT_FG_Table[16];
@@ -132,9 +133,18 @@ void VGA_SetCGA4Table(Bit8u val0,Bit8u val1,Bit8u val2,Bit8u val3) {
 #else
 			(total[(i >> 6) & 3] << 0  ) | (total[(i >> 4) & 3] << 8  ) |
 			(total[(i >> 2) & 3] << 16 ) | (total[(i >> 0) & 3] << 24 );
+#endif
+		CGA_4_HiRes_Table[i]=
+#ifdef WORDS_BIGENDIAN
+			(total[((i >> 0) & 1) | ((i >> 3) & 2)] << 0  ) | (total[((i >> 1) & 1) | ((i >> 4) & 2)] << 8  ) |
+			(total[((i >> 2) & 1) | ((i >> 5) & 2)] << 16 ) | (total[((i >> 3) & 1) | ((i >> 6) & 2)] << 24 );
+#else
+			(total[((i >> 3) & 1) | ((i >> 6) & 2)] << 0  ) | (total[((i >> 2) & 1) | ((i >> 5) & 2)] << 8  ) |
+			(total[((i >> 1) & 1) | ((i >> 4) & 2)] << 16 ) | (total[((i >> 0) & 1) | ((i >> 3) & 2)] << 24 );
 #endif
 	}	
 }
+
 void VGA_Init(Section* sec) {
 	vga.draw.resizing=false;
 	vga.mode=M_ERROR;			//For first init
diff --git a/src/hardware/vga_draw.cpp b/src/hardware/vga_draw.cpp
index fb54ce9c..b8f07a84 100644
--- a/src/hardware/vga_draw.cpp
+++ b/src/hardware/vga_draw.cpp
@@ -58,6 +58,20 @@ static Bit8u * VGA_Draw_2BPP_Line(Bitu vidstart,Bitu panning,Bitu line) {
 	return TempLine;
 }
 
+static Bit8u * VGA_Draw_2BPPHiRes_Line(Bitu vidstart,Bitu panning,Bitu line) {
+	line*=8*1024;Bit32u * draw=(Bit32u *)TempLine;
+	for (Bitu x=0;x<(vga.draw.blocks>>1);x++) {
+		Bitu val1=vga.mem.linear[vidstart+line];
+		Bitu val2=vga.mem.linear[vidstart+1+line];
+		vidstart+=2;
+		if((vga.crtc.mode_control & 0x01) == 0) // CGA compatible addressing
+			vidstart &= 0x1dfff;
+		*draw++=CGA_4_HiRes_Table[(val1>>4)|(val2&0xf0)];
+		*draw++=CGA_4_HiRes_Table[(val1&0x0f)|((val2&0x0f)<<4)];
+	}
+	return TempLine;
+}
+
 static Bitu temp[643]={0};
 
 static Bit8u * VGA_Draw_CGA16_Line(Bitu vidstart,Bitu panning,Bitu line) {
@@ -513,9 +527,12 @@ void VGA_SetupDrawing(Bitu val) {
 		doubleheight=true;
 		if (machine==MCH_TANDY) doublewidth=(vga.tandy.mode_control & 0x10)==0;
 		else doublewidth=(vga.tandy.gfx_control & 0x8)==0x00;
-		vga.draw.blocks=width * (doublewidth ? 4:8);
+//		vga.draw.blocks=width * (doublewidth ? 4:8);
+		vga.draw.blocks=width * 4;
 		width=vga.draw.blocks*2;
-		VGA_DrawLine=VGA_Draw_2BPP_Line;
+		if ((machine==MCH_TANDY && (vga.tandy.gfx_control & 0x8)) ||
+			(machine==MCH_PCJR && (vga.tandy.mode_control==0x0b))) VGA_DrawLine=VGA_Draw_2BPPHiRes_Line;
+		else VGA_DrawLine=VGA_Draw_2BPP_Line;
 		break;
 	case M_TANDY16:
 		aspect_ratio=1.2;
diff --git a/src/hardware/vga_other.cpp b/src/hardware/vga_other.cpp
index 3453c73b..0d35895f 100644
--- a/src/hardware/vga_other.cpp
+++ b/src/hardware/vga_other.cpp
@@ -191,7 +191,8 @@ static void write_color_select(Bit8u val) {
 		break;
 	case M_TANDY4:
 		{
-			if (IS_TANDY_ARCH && (vga.tandy.gfx_control & 0x8)) {
+			if ((machine==MCH_TANDY && (vga.tandy.gfx_control & 0x8)) ||
+				(machine==MCH_PCJR && (vga.tandy.mode_control==0x0b))) {
 				VGA_SetCGA4Table(0,1,2,3);
 				return;
 			}
diff --git a/src/ints/int10_put_pixel.cpp b/src/ints/int10_put_pixel.cpp
index 241d8d35..5992a059 100644
--- a/src/ints/int10_put_pixel.cpp
+++ b/src/ints/int10_put_pixel.cpp
@@ -28,16 +28,32 @@ void INT10_PutPixel(Bit16u x,Bit16u y,Bit8u page,Bit8u color) {
 	switch (CurMode->type) {
 	case M_CGA4:
 		{
-				Bit16u off=(y>>1)*80+(x>>2);
-				if (y&1) off+=8*1024;
-				Bit8u old=real_readb(0xb800,off);
-				if (color & 0x80) {
-					color&=3;
-					old^=color << (2*(3-(x&3)));
+				IO_Write(0x3d4,0x09);
+				if (IO_Read(0x3d5)==1) {
+					Bit16u off=(y>>1)*80+(x>>2);
+					if (y&1) off+=8*1024;
+
+					Bit8u old=real_readb(0xb800,off);
+					if (color & 0x80) {
+						color&=3;
+						old^=color << (2*(3-(x&3)));
+					} else {
+						old=old&cga_masks[x&3]|((color&3) << (2*(3-(x&3))));
+					}
+					real_writeb(0xb800,off,old);
 				} else {
-					old=old&cga_masks[x&3]|((color&3) << (2*(3-(x&3))));
+					Bit16u off=(y>>2)*160+((x>>2)&(~1));
+					off+=(8*1024) * (y & 3);
+
+					Bit16u old=real_readw(0xb800,off);
+					if (color & 0x80) {
+						old^=(color&1) << (7-(x&7));
+						old^=((color&2)>>1) << ((7-(x&7))+8);
+					} else {
+						old=old&(~(0x101<<(7-(x&7)))) | ((color&1) << (7-(x&7))) | (((color&2)>>1) << ((7-(x&7))+8));
+					}
+					real_writew(0xb800,off,old);
 				}
-				real_writeb(0xb800,off,old);
 		}
 		break;
 	case M_CGA2:
@@ -56,8 +72,10 @@ void INT10_PutPixel(Bit16u x,Bit16u y,Bit8u page,Bit8u color) {
 		break;
 	case M_TANDY16:
 		{
-			Bit16u off=(y>>2)*160+(x>>1);
-			off+=(8*1024) * (y & 3);
+			IO_Write(0x3d4,0x09);
+			Bit8u scanlines_m1=IO_Read(0x3d5);
+			Bit16u off=(y>>((scanlines_m1==1)?1:2))*(CurMode->swidth>>1)+(x>>1);
+			off+=(8*1024) * (y & scanlines_m1);
 			Bit8u old=real_readb(0xb800,off);
 			Bit8u p[2];
 			p[1] = (old >> 4) & 0xf;