Many thanks to both of you (Dinho and Dag). You have both answered my question, but in different ways. Until now I have only used the ICD to debug small fragmets of code - typically a device driver function. Dinho confirmed that for small apps then he had no problems - neither have I. Dag mentioned the reservation of the last 256 words of code memory for the ICD. This would obviously be important in a very large app. Good work! Alan Embedded Systems Engineer Microtima Ltd Ouseburn Mews 3-7 Stepney Bank Newcastle upon Tyne NE1 2PW Tel: 0191 2304411 Fax: 0191 2304422 -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.