The logical circuits (Lattice ISP) in a Milan can be changed later on. A so called JEDEC file contains these circuits. They are written into the chip by a special software.
There are three different JEDEC files for the Milan (included in the archive

LSI1024O.JED The file with the old and wrong circuits. It is only here for the unlikely case that the Milan doesn't work properly after the update.
LSI1024N.JED The update file for normal Milans. This is the file of your choice. Try the update with this file first!
LSI1024S.JED The update file for sensitive Milans. You should try this file only in case the update wasn't successful with the LSI1024N.JED.

In any case you have to make sure, that you rename the file into LSI1024.JED when you copy it onto the floppy disk! Otherwise it won't be found by the software!

Ingo Lafrenz 2001