I'm designed my own 16C6X, 167X, 16C8X programmer, and so far it works great, but I'm really confused about some of the data given in the data sheet on In Circuit Serial Programming of these devices. In the flow chart on programming the Configuration Word and ID locations, it starts with the load configuration command. Earlier in the data sheet the load configuration command is said to be followed by data. Ok, fine, but nothing seems to be done with the data at this point. If you keep following the flowchart, the next 2 things you can do are either an increment address command, or a program cycle (which begins with its own load data command). So it boils down to this: What data follows the load configuration? Do I use the load configuration command instead of the load data command (in the "program cycle")? thanks, Matt ----------------------------- Matt Bennett | mjb@hazmat.com | http://www.hazmat.com/~mjb/ |