use custom roz implementation to allow for further tweaking, whatever this does it doesn't appear to be standard (I still haven't figured it out properly after 10 years) so will need it (nw)

src/mame/video/mb60553.c

@@ -181,6 +181,85 @@ void mb60553_zooming_tilemap_device::set_gfx_region( int gfx_region)
 	m_m_gfx_region = gfx_region;
 }
 
+
+
+
+
+void mb60553_zooming_tilemap_device::draw_roz_core(screen_device &screen, bitmap_ind16 &destbitmap, const rectangle &cliprect,
+		UINT32 startx, UINT32 starty, int incxx, int incxy, int incyx, int incyy, bool wraparound)
+{
+	// pre-cache all the inner loop values
+	//const rgb_t *clut = m_palette->palette()->entry_list_adjusted();
+	const int xmask = m_tmap->pixmap().width() - 1;
+	const int ymask = m_tmap->pixmap().height() - 1;
+	const int widthshifted = m_tmap->pixmap().width() << 16;
+	const int heightshifted = m_tmap->pixmap().height() << 16;
+	UINT8 mask = 0x1f;// blit.mask;
+	UINT8 value = 0x10;// blit.value;
+	bitmap_ind16 &srcbitmap = m_tmap->pixmap();
+	bitmap_ind8 &flagsbitmap = m_tmap->flagsmap();
+
+	// pre-advance based on the cliprect
+	startx += cliprect.min_x * incxx + cliprect.min_y * incyx;
+	starty += cliprect.min_x * incxy + cliprect.min_y * incyy;
+
+	// extract start/end points
+	int sx = cliprect.min_x;
+	int sy = cliprect.min_y;
+	int ex = cliprect.max_x;
+	int ey = cliprect.max_y;
+
+	// loop over rows
+	while (sy <= ey)
+	{
+		// initialize X counters
+		int x = sx;
+		UINT32 cx = startx;
+		UINT32 cy = starty;
+
+		// get dest and priority pointers
+		UINT16 *dest = &destbitmap.pix(sy, sx);
+
+		// loop over columns
+		while (x <= ex)
+		{
+			if (wraparound)
+			{
+				if ((flagsbitmap.pix((cy >> 16) & ymask, (cx >> 16) & xmask) & mask) == value)
+				{
+					*dest = (srcbitmap.pix((cy >> 16) & ymask, (cx >> 16) & xmask));
+				}
+			}
+			else
+			{
+				if (cx < widthshifted && cy < heightshifted)
+				{
+					if ((flagsbitmap.pix(cy >> 16, cx >> 16) & mask) == value)
+					{
+						*dest = (srcbitmap.pix(cy >> 16, cx >> 16));
+					}
+				}
+			}
+
+			// advance in X
+			cx += incxx;
+			cy += incxy;
+			x++;
+			dest++;
+			//pri++;
+		}
+
+		// advance in Y
+		startx += incyx;
+		starty += incyy;
+		sy++;
+	}
+}
+
+
+
+
+
 /* THIS IS STILL WRONG! */
 void mb60553_zooming_tilemap_device::draw( screen_device &screen, bitmap_ind16& bitmap, const rectangle &cliprect, int priority)
 {
@@ -211,15 +290,12 @@ void mb60553_zooming_tilemap_device::draw( screen_device &screen, bitmap_ind16&
 
 		clip.min_y = clip.max_y = line;
 
-		m_tmap->draw_roz(screen, bitmap, clip, startx<<12,starty<<12,
+		draw_roz_core(screen, bitmap, clip, startx<<12,starty<<12,
 				incxx,0,0,incyy,
-				1,
-				0,priority);
+				1
+				);
 
 	}
-
-
-
 }
 
 tilemap_t* mb60553_zooming_tilemap_device::get_tilemap()

src/mame/video/mb60553.h

@@ -33,6 +33,9 @@ public:
 	DECLARE_READ16_MEMBER(vram_r);
 	DECLARE_READ16_MEMBER(line_r);
 
+	void draw_roz_core(screen_device &screen, bitmap_ind16 &destbitmap, const rectangle &cliprect,
+		UINT32 startx, UINT32 starty, int incxx, int incxy, int incyx, int incyy, bool wraparound);
+
 protected:
 	virtual void device_start();
 	virtual void device_reset();