I have solved the mystery of my malfunctioning XS board. The actual problem is my scanner. As with most scanners it has a wake up sequence which grabs control of the port via a vxd. The XSTOOLs software is running in a DOS window and cannot over ride this. This is independent of Win95/Win98, but I am told that this problem could appear almost at random. The scanner vxd is set to share with the printer and interprets XSTOOLs output as printer instructions. Then the VXD translates them in some way which invalidates the data that XSLOAD is trying to download to the XS Board.