Do any of the small development systems work in DOS? What does the program file for such a chip look like? I have this picture in my mind of a chip containing several of the usual logic gates such as And and Or plus a few inverters or flip-flops and then some kind of equation to connect them together in the way desired to build the particular application. I've been hearing about GAL's and PAL's for about ten years, but I haven't gotten in to any actual work with them. I seem to recall being scared away when I found out how much the development systems cost. Martin McCormick WB5AGZ Stillwater, OK OSU Center for Computing and Information Services Data Communications Group