diff --git a/asm/drawtile.s b/asm/drawtile.s
index 9fb871c..52394f7 100644
--- a/asm/drawtile.s
+++ b/asm/drawtile.s
@@ -5,10 +5,48 @@
  case on
  longa on
  longi on
-
+ 
 Dummy3 start ASMCODE
 	end
 
+*
+* void draw_tile(U8 tileNumber)
+*
+draw_tile start ASM_CODE
+iTileNo equ 5
+
+	phb
+	lda iTileNo,s
+	ora |draw_tilesBank
+	asl A
+	tax
+	
+	lda |fb
+	tay
+	adc #4
+	sta |fb
+	
+	lda 3,s
+	sta iTileNo,s
+	lda 1,s
+	sta iTileNo-2,s
+	
+	lda #$0101
+	sta 1,s
+	plb
+	plb
+TILEBANK3 entry
+	lda >$880005,x
+	sta >TILEBANK4+1
+TILEBANK4 entry
+	jsl >$880000
+
+	plb
+	rtl
+*-------------------------------------------------------------------------------
+    end
+	
+
 *
 * void DrawTile(short offset, short tileNo)
 *
@@ -63,6 +101,8 @@ iBank equ 4
 	lda iBank,s
 	sta >TILEBANK+3
 	sta >TILEBANK2+3
+	sta >TILEBANK3+3
+	sta >TILEBANK4+3
 	rep #$30
 	lda 2,s
 	sta iBank,s
diff --git a/include/draw.h b/include/draw.h
index 756257f..6aec6a5 100644
--- a/include/draw.h
+++ b/include/draw.h
@@ -29,7 +29,7 @@ extern U8 *draw_tllst;
 #ifdef GFXPC
 extern U16 draw_filter;
 #endif
-extern U8 draw_tilesBank;
+extern U16 draw_tilesBank;
 extern rect_t draw_STATUSRECT;
 extern rect_t draw_SCREENRECT;
 
diff --git a/include/maps.h b/include/maps.h
index 1f9c915..a9577c8 100644
--- a/include/maps.h
+++ b/include/maps.h
@@ -138,7 +138,7 @@ extern U8 map_frow;
 /*
  * tiles offset
  */
-extern U8 map_tilesBank;
+extern U16 map_tilesBank;
 
 extern void map_expand(void);
 extern void map_init(void);
diff --git a/include/system.h b/include/system.h
index e2591fe..38de33a 100644
--- a/include/system.h
+++ b/include/system.h
@@ -186,7 +186,7 @@ extern volatile unsigned long* tick;
 
 // GS Rendering Stuff
 extern void SetTileBank(short bank);
-extern void DrawTile(int offset, int tileNo);
+extern void DrawTile(int offset, U16 tileNo);
 extern void SetSpriteBanks(short b0, short b1, short b2, short b3);
 extern void DrawSprite(int offset, int SpriteNo);
 
diff --git a/src/devtools.c b/src/devtools.c
index 8dc6f42..1ead93e 100644
--- a/src/devtools.c
+++ b/src/devtools.c
@@ -64,7 +64,11 @@ devtools_run(void)
       draw_setfb(64, 30 + i * 0x0a);
       draw_tile((i<10?0x30:'A'-10) + i);
     }
+	#ifdef GFXGS
+    draw_tilesBank = pos << 8;
+	#else
     draw_tilesBank = pos;
+	#endif
     for (i = 0; i < 0x10; i++)
       for (j = 0; j < 0x10; j++) {
 	draw_setfb(80 + j * 0x0a, 30 + i * 0x0a);
@@ -172,7 +176,11 @@ devtools_run(void)
     draw_setfb(4, 4);
     draw_tilesBank = 0;
     draw_tilesListImm(s);
+	#ifdef GFXGS
+    draw_tilesBank = pos2<<8;
+	#else
     draw_tilesBank = pos2;
+	#endif
     for (l = 0; l < 8; l++)
       for (k = 0; k < 4; k++)
 	for (i = 0; i < 4; i++)
diff --git a/src/draw.c b/src/draw.c
index 0b983ec..a09f602 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -88,7 +88,7 @@ U8 *draw_tllst;    /* pointer to tiles list */
 #ifdef GFXPC
 U16 draw_filter;   /* CGA colors filter */
 #endif
-U8 draw_tilesBank; /* tile number offset */
+U16 draw_tilesBank; /* tile number offset */
 rect_t draw_STATUSRECT = {
   DRAW_STATUS_SCORE_X, DRAW_STATUS_Y,
   DRAW_STATUS_LIVES_X + 6 * 8 - DRAW_STATUS_SCORE_X, 8,
@@ -100,7 +100,7 @@ rect_t draw_SCREENRECT = { 0, 0, 320, SYSVID_HEIGHT, NULL };
 /*
  * private vars
  */
-static U8 *fb;     /* frame buffer pointer */
+U8 *fb;     /* frame buffer pointer */
 
 
 /*
@@ -234,13 +234,14 @@ draw_tilesSubList()
  * draw_filter: CGA colors filter
  * fb: CHANGED (see above)
  */
+#ifndef GFXGS
 void
 draw_tile(U8 tileNumber)
 {
 #ifdef GFXGS
 	//$$JGA TODO convert to ASM
 
-	int tileNo = (((int)draw_tilesBank)*256)+tileNumber;
+	U16 tileNo = draw_tilesBank | tileNumber;
 
 	//printf("fb=%04x tileNo=%04x\n", (int)fb, tileNo);
 	//sys_sleep(1000);  // Wait 1 second
@@ -289,6 +290,7 @@ draw_tile(U8 tileNumber)
   fb += 8;  /* next tile */
 #endif
 }
+#endif
 
 /*
  * Draw a sprite
diff --git a/src/maps.c b/src/maps.c
index 22c96f8..b6b1838 100644
--- a/src/maps.c
+++ b/src/maps.c
@@ -48,7 +48,7 @@
 U8 map_map[0x2C][0x20];
 U8 map_eflg[0x100];
 U8 map_frow;
-U8 map_tilesBank;
+U16 map_tilesBank;
 
 
 /*
@@ -105,8 +105,11 @@ map_init(void)
   draw_filter = 0xffff;
   map_tilesBank = (map_submaps[game_submap].page == 1) ? 3 : 2;
 #endif
-#if defined(GFXST) || defined(GFXGS)
+#ifdef GFXST
   map_tilesBank = (map_submaps[game_submap].page == 1) ? 2 : 1;
+#endif
+#ifdef GFXGS
+  map_tilesBank = (map_submaps[game_submap].page == 1) ? 0x200 : 0x100;
 #endif
   map_eflg_expand((map_submaps[game_submap].page == 1) ? 0x10 : 0x00);
   map_expand();
diff --git a/src/system.c b/src/system.c
index c727fe8..fc00f1a 100644
--- a/src/system.c
+++ b/src/system.c
@@ -80,7 +80,7 @@ U32
 sys_gettime(void)
 {
 #ifdef IIGS
-	return tick[0] * 16;
+	return tick[0] << 4;
 #else
   static U32 ticks_base = 0;
   U32 ticks;
@@ -102,7 +102,7 @@ sys_sleep(int s)
 {
 #ifdef IIGS
 	// on GS we're going to work in ms, also we don't sleep, we just wait
-	while (s > 0)
+	while (s > 8)
 	{
 		sysvid_wait_vblank();
 		s -= 16; // About 1/60th of a second