Hello to all:)
Thank you very much sanni, by this instruction manual so large and so detailed. This must have been an impressive and very laborious work for you.
I'm using very well my holidays week 
Three days I've been working on my electronic Assembly and I still don't know why it does not read the save data of any of the cartridges that I have placed in it, only reads the Rom.
I apologize for my stupidity and my ignorance, but I can't find the fault in my assembly.
I've revised it dozens of times, without finding any error, I have checked the wiring, I have changed the power supply several times and then I decided to use a battery, to avoid electrical noise. I have changed the memory card by different each other several times, everything has been useless, I can not get it work and read the save data.
Then I tried to change the version of arduino, without positive result, I'm back up libraries several times, same result, I have uploaded the program arduino card several times, also without result. I'm very frustrated, I don't know what more can I do.
Then I thought, this can be a problem of clock signal or something similar and I have decided to check the clock signal with my oscilloscope in pin 57(PH1) CPU_CLK, this has left me amazed, here is a reading with too much noise and a triangular wave, ranging between 28 Mhz and 32 Mhz. should be here in this pin a perfectly square wave signal is not true? with 1.6 Mhz. I apologize for my ignorance.
Please sanni can you tell me, What signal must be present at this pin 57(PH1) CPU_CLK, thank you.
I must take my Chinese clone of the arduino mega 2560 and delicately let it fall into the dustbin. Ha, ha, ha
Believe me, I very much regret the inconvenience that I am causing, due to my ignorance and I apologise humbly, thank you to all.
