diff --git a/src/hardware/vga_draw.cpp b/src/hardware/vga_draw.cpp
index 2c0f5880..56f7da8c 100644
--- a/src/hardware/vga_draw.cpp
+++ b/src/hardware/vga_draw.cpp
@@ -901,7 +901,7 @@ void VGA_SetupDrawing(Bitu val) {
 		doubleheight=true;
 		vga.draw.blocks=width*2;
 		if (vga.tandy.mode_control & 0x1) {
-			if ( vga.tandy.mode_control & 0x10 ) {
+			if (( machine==MCH_TANDY ) && ( vga.tandy.mode_control & 0x10 )) {
 				doublewidth = false;
 				vga.draw.blocks*=2;
 				width=vga.draw.blocks*2;
diff --git a/src/hardware/vga_other.cpp b/src/hardware/vga_other.cpp
index a57765d4..1c723d93 100644
--- a/src/hardware/vga_other.cpp
+++ b/src/hardware/vga_other.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: vga_other.cpp,v 1.20 2007-01-24 16:29:09 harekiet Exp $ */
+/* $Id: vga_other.cpp,v 1.21 2007-02-01 16:24:03 c2woody Exp $ */
 
 #include <string.h>
 #include <math.h>
@@ -400,8 +400,8 @@ static void write_tandy(Bitu port,Bitu val,Bitu iolen) {
 		break;
 	case 0x3df:
 		vga.tandy.line_mask = val >> 6;
-		vga.tandy.draw_bank = val & 0x7;
-		vga.tandy.mem_bank = (val >> 3) & 0x7;
+		vga.tandy.draw_bank = val & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
+		vga.tandy.mem_bank = (val >> 3) & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
 		TandyCheckLineMask();
 		VGA_SetupHandlers();
 		break;
@@ -420,8 +420,8 @@ static void write_pcjr(Bitu port,Bitu val,Bitu iolen) {
 		break;
 	case 0x3df:
 		vga.tandy.line_mask = val >> 6;
-		vga.tandy.draw_bank = val & 0x7;
-		vga.tandy.mem_bank = (val >> 3) & 0x7;
+		vga.tandy.draw_bank = val & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
+		vga.tandy.mem_bank = (val >> 3) & ((vga.tandy.line_mask&2) ? 0x6 : 0x7);
 		vga.tandy.draw_base = &MemBase[vga.tandy.draw_bank * 16 * 1024];
 		vga.tandy.mem_base = &MemBase[vga.tandy.mem_bank * 16 * 1024];
 		TandyCheckLineMask();