One time programmable chips do not use a crystal window. They are set up to be programmed one time and thus, do not have any means through which to be erased and reused.

You only get one shot at them. Once they are burned, they are burned for good. I have not seen a factory chip from an 85 this way, but I haven't seen many by any means.

 

Thanks HighHopes, glad to see that some are willing to help.

Is this one time use just privy to the 85 style or 27c32 chips, or do they too have eeprom (reusable chips available) like the AT29c256 chips?

I guess what I am trying to ask is, if I see a chip without a window in an 85 vette, is a one time burn deal?

Cheers.

 

ive seen a handful of OTP 2732's in delco remans. other than that no havent seen them at all. as far as i know there has never been a 2832 but to kill you they make a 2816 which is half the size of a 32. arrggh. the best bet is to get 27c32b from www.unicornelectronics.com ive had lots of use out of these chips. you need to call on the phone they have a larges stock. now youll pay more then on ebay but ive programmed and erased these b's about 10x's each and there fine. so for the extra few bucks there worth it. i think they last longer becuase they are 12volts not 21. thats also easier on the programmer as well.

see you later.

 

Thanks funstick! I will order a few for us. Appreciate it!