I recently purchased a GQ-4X to burn EPROM for APPLE IIe. I can write without problem "2764", EPROMs are working in the APPLE (so pinouts are OK and compatible with original chips I guess). But I can't read the corresponding original ROMS with the GQ-4X. I got full of "FF" for all the memory readed... Nevertheless I can read Original ROMs corresponding to 2732 and even 27128. But none with 2764... I can re-read my own burned EPROM 2764 without problem. Is it normal that ROMS fully compatibles with 2764 are not necessarily readable with the GQ-4X ? I am a novice in the burning so sorry if the questions are stupid... I hope you can help me ! Best Regards