Convert PAT to BMP

Pretty much every type of  pattern (.pat) files are just renamed raster, or in some rare cases vector graphics. You can always try to rename pat extension to bmp/jpg and see if that works and you can open these files with some graphics editor. Except for that, some programs can directly import patterns and re-save them to another type of graphics, but it is unlikely some converter designed just for pat to bmp conversion exists.