It would not surprise me to find that this was a mask rom. I looked through all of the databooks that I could see for the time period that you were talking about, and nothing even close to that part number exists. However, mask roms of similar size to what you described do exist. I know some vendors label the mask roms with a 'special' part number which identifies which mask got 'programmed' into the chip. On Mon, Feb 19, 2018 at 8:04 PM, andrew kelley wrote: > Correct. But if I can write 0s to it (which I can't) proves something in > this code isn't right. I can't erase it either. If it was otp, I could at > least 0 out the chip and not be able to erase.. > > Well, I guess I'll just end up modifying the boards and repotting them > since absolutely no one has a DS on it. Nothing on Google for a ds, found > some code but it doesn't work. This was my last try. > > Thanks all. > Andrew > > On Sunday, February 18, 2018, wrote: > > > > > "(But then I ought to be able to program it blank it out to all 0's and > > finish it off & just not erase )" > > > > Hi Andrew - not sure exactly what you mean here but "blank" NV memory > > generally means all 1's. If you "blank" it by writing 0's to it you > > probably won't be able to program it. Erasing will usually (always?) se= t > > the memory to all 1's. > > > > Stephen > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forrestc@imach.com | http://www.packetflux.com --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .