74LS05 is open collector while 74LS06 is not. Also, Is your Vpp okay? On 6/12/07, microsoftwarecontrol wrote: > used for 2 years, my lovely kit96 pcb (LS05 made) broken into two pieces. > > I tried 3 days already, try to made new kit96 pcb with TI's 74ls06N, but after 3 version, > no one works. I can read my old programed pics properly, all bits and ROM. > But, writing seems only write 0. After writing, all read back is 0. > > what wrong? same PC, same cable, just another pcb made of ls06. why it persistently > write only 0? > > it suppose to be a simply pcb. but I can not finger out what is going on with my new kit96 pcb now. > -- Chetan Bhargava Web: http://www.bhargavaz.net Blog: http://microz.blogspot.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist