As mentioned in earlier posts to comp.lang.ada, John's book has received only a few positive reviews and a number of very negative ones at amazon.com. The unfortunate effect is that the summary "stars" rating -- what one sees initially, without digging -- is IMHO very misleading and does damage to a fine book. Several people have indicated on c.l.a. that they had a high regard for the book, especially the second edition. Let me suggest to everyone that has both read and enjoyed John's book to go to www.amazon.com, do a ISBN search on 0201342936, and enter a review. --- Pat Rogers Training and Consulting in: http://www.classwide.com Deadline Schedulability Analysis [log in to unmask] Software Fault Tolerance (281)648-3165 Real-Time/OO Languages