Hi Wade, A small 284 Kb 1tcr.phi should not cause Chimera DelPhi Viewer to request too much memory. I suspect the problem is that the DelPhi Viewer extension is not correctly reading the size of the data file from the header. It thinks the phi file is enormous and requests too much memory. The most probable reason for that is the byte order of the DelPhi file is opposite of what is expected. This happens when the Phi file is written on another computer which represents 4 byte integers using the reverse byte order of the computer you are trying to read the data with. Both the Volume Viewer and DelPhi extensions attempt to identify the correct byte order but I am not sure if that works for the DelPhi Viewer. It would be worth trying to open the 1tcr.phi file with the Chimera File/Open... to see if volume viewer can open it. Another possibility is that Chimera really has used up all your computer's memory. How much memory does your machine have? If you email the 1tcr.phi file I can try looking at it with DelPhi Viewer. Tom