My Willem 3.1 started bugging on me last week, First Write Sector Error 0, then after trying a bunch Sector 220, then 510. Finally got it to work.

Now It get Sector 0 again and IO traced it to a bad DIP switch, replaced it and still got nothing, when I do a hardware test, it sometimes checks out all fine, sometimes not.

I can read a Chip (all 00 in the buffer) and then reprogram what a just read) It was letting me earase for a while but now it times out.

BTW: 29c256 Chips with power @6volts. Alway worked flawlessly till now.

 

sounds like your willem went poop on you, time for a new one.

 

Well, someone thought it was the chips but there not. I just programed them at school and all went well.