Hi PIC-listers First thank you to all, that replyed to my former message. I have greate troubles with programming a 16C74. I use the propic ver. 1 programmer, but when I read the part, it reads 0x3800 at adress 0 instead of 0x3FF, which would be expected. It is the same problem with 2 PICs, which causes me to think that it is my programmer. I have UV erased the parts for several hours. When I check the programming voltages in the "voltage check" in the propic program, they are all OK. It is my hope, that someone here could help me to solve this problem. Thanks in advance. Henrik Nowak