ok it reports the correct ID.Ive seen the jedec standard.Up until 2000 there was no requirement to include ID`s,the AM27c010 does support auto check.Also the AM27c010 was available in OTP (one time programmable) parts,maybe thats what youve got ? if it can`t be erased ,or like you said its just faulty.Ive got a tl866cs and i`m more than happy with it,its far easier to use than my willem programmer.