Hello, Hope I'm not being to stupid here, but I think there's a portability problem with these functions for anything other than byte oriented data because the endian mode in memory is system dependent whereas for files it will depend on the format specified for the file. I would like to suggest additional functions.. hPutBuf<N><E> hGetBuf<N><E> where N=16,32,64 and E=L(ittle),B(ig) The endian mode refers to the file format and necessary conversion to/from the systems "native" mode is done automatically. It would be nice to have similar functions for reading and writing individual Words too. There would be a similar problem with hPutArray and hGetArray if they were used for reading writing arrays of words other than Word8 (using castIOUArray perhaps?) Just an idea. Regards -- Adrian Hey