Which image viewer to use - ENV=contents of SAS_IMAGEVIEWER true Bring SAOtng up? Load a new image? Name of the image data set to display true Read region specs? Display contents of (ASC)region table? Name of table containing (ASC)regions true Region specs true Flip displayed image around X? Flip displayed image around Y? Bring SAOtng down? Send additional commands? commands to send true Expect output as result of sent commands? received data after send command true