Hi, We found what looks like a brilliant assembler and simulator for the PIC 16C84. However, it doesnt seem to recognise source code which compiles and runs perfectly with MPASM. It is available from http://www.iglou.com/ITU/cessim.htm. Any ideas please why we cannot use this software? David Dobbs //////////////////////////////////////////////////////////////// /// Just to let you know we have a web page at ' http://www.innotts.co.uk/~dobbs/ ' //////////////////////////////////////////////////////////////// ///