robert@xxxxxxxxxxxxxxxxxx wrote: > illumread crashes when trying to do a measurement if there is no instrument > attached or if the Argyll driver is not loaded (for an i1Pro). I can't reproduce this. If I have no instrument connected on WinXP I get: illumread -v test.sp Press 1 .. 7 1) Measure direct illuminant 2) Measure illuminant reflected from paper 3) Measure paper 4) Select another instrument, Currently 1 ( 'COM1') 5) Compute illuminant spectrum, average result with 0 previous readings & save it 6) Compute illuminant spectrum from this reading & save result 7) Exit If I try and measure something I get: '1' !!! Unknown, inappropriate or no instrument detected !!! '4' 1 = 'COM1' 2 = 'COM3' 3 = 'COM4' Select device 1 - 3: Can you be more specific about how you caused a crash ? Graeme Gill.