>>74LS139 >>pin-12 -> 6164,pin-20 >>pin-13 -> 27c256,pin-20 > > > Hi, > > Are these connections ok? What 74LS139 pins must be swapped? ¿11<->12 or > 12<->13? I am a bit confused. Argh. That's what happens when one doesn't get enought sleep... It's 11<->12 Take a look at the updated documentation, the wiring is now correct there. Regards, FRS