I am using a linux environment with version 4 running in system .. It has a bash shell running.. and the alliance downloaded from alliance/~ludo... I tried to running the addaccu in the tutorial which ran perfectly which gave me some errors only in the pattern of addaccu ..I dont know whether the addaccu.pat file consist of right patterns. so I got basically a few compilation errors.. the errors shot up with when i ran asimut addaccu addaccu specifications It gave me error in pattern file . so i got a feeling that the pattern file dosnt have proper specifications.. I have another doubt of how to study the rules and alter them ??? please send me some more details of the addaccu structure.. and if any more information can be got about the datapath structure .. Thanks waiting for your reply Manikandan Viswanath Off/College Res: Clarkson University 34-1/2 Market Street ECE Dept., Potsdam P.O. #5722 New York Potsdam, Newyork -13699 NY-13676 Ph . : 315 268 3764 Ph : 315 265 3799