I admit you that I had not well understood But now it is good A last question R1 and R2 = ?? ohm Because I think that I am going to proceed as you Ground----------R1 (2 ohm)-------------{+3.3v}-------------R2 (1 ohm)-----------------+5v That should do the trick, i worked that out quickly and I havn...

Well, yes and no. Removing a SOP mask ROM and replacing it with another is definitely a lot easier than having to wire in an EPROM pin by pin. But the EEPROM I used isn't easily obtainable, and my programmers don't support them. I would have to build my own adapter for my programmer, they don't mak...