Code:
  PowerDraw.TextureMap( Image, pBounds4(myX, myY, Image.PatternWidth , Image.PatternHeight), cColor1($00FFFFFF), tPattern(0), effectSrcAlpha)
I dunno, is it correct, but I do and it works. Here Image is TAGFImage with alpha transparency (iso-tile). And if you want better perfomance, use one big Image object and then draw only patterns of it. Otherwise you could end by very low framrate.