What is the best signal interface for PC ?

[_q12x_]

nope , not good. I tested in other simulator that circuit with the transistor, which very much resembles your much simpler version and I applaud its simplicity, I like it very much actually, more than mine.
But the problem with both circuits here is that Pressed button !!! As long as I am keeping it pressed, it will "count" 0V ! Which is not good. So if im counting 10s with the button pressed down to 0V, the circuit will stay to 0V 10s. WHen I release the button, it will count another extra 50ms based on the cap and res values that I chose and reach 5V. So this behavior is NO BUENO !
What I really need is like this: Press ONCE the button and keep it pressed. But the circuit will not stay at 0V. It will jump from 5V to 0V in the moment the button made the contact, count internally those 50ms, and rise up to 5V by itself, while my button is still pressed. When I release the button from its contacts, the circuit still remains at 5V, unchanged. Only when I press the button again. and at the very first contact , the whole logic repeats again. Clear now?
I am trusting the good old 555 timer to do it. But... I didnt actually stay down to think about it. I only figure out how the logic should be, the one I just described so far.
Remember this is waaaay a SIDE mini-project or dare. Haha. Not at all the main quest Im in. Its a cute side quest. A curiosity.

 

[marconi]

Please draw me the circuit you have connected to the CEbar pin.

 

[_q12x_]

Good day sir, Mister @marconi and others that are reading my thread, please read this page --HERE-- I put it in discussion last night but unfortunately the guys that are answering me are too undecided. Usually they are of great help but here, in this case, this specific subject is like a black cat for them. They keep some inexplicable distance.
Its not that long, is 1page and a half of reading, until that big blue screen screenshot of mine. And you can skip many unimportant points. See if it is ringing a bell for you and help me progress and push this "programming a RAM chip with an external file" to its final conclusion.
Thank you in advance!

 

[_q12x_]

Please draw me the circuit you have connected to the CEbar pin.

you mean this one? Yours is better ! ...but both inutilizable.
we must think on another BETTER circuit. This is NO BUENO.

 

[marconi]

Please answer my question. SHow me exactly how you modelled my circuit and actually connected it to CEbar. Did you pass the pulse from my circuit through those relay contacts ? Did you do as in the attachment?

S1 is is NO pushbutton for programming. S2 is the NO switch to tell the chip to operate as a RAM ie programming over. When in programming mode S2 must be open. You know already what to do with the OEbar pin for programming mode and RAM mode.

 

[_q12x_]

This is the last circuit I made following your instructions.
I am now pretty sure how to connect the RAM chip in the next stage. No worries.
I made some very interesting advancements from 2 days in a row until today, about how to manually program a RAM. I start to get it, and also how to program a RAM from a file, which is very important.
I did not used the RAM or any relay in this last circuit. That RAM is floating there.

 

[marconi]

Have you run this circuit in proteus?

 

[_q12x_]

Have you run this circuit in proteus?

yes

 

[marconi]

I deserve better than ‘yes’.

 

[_q12x_]

I deserve better than ‘yes’.

Check my answer in #93 ...also your immediate answer next in #94
I was completely concentrated these last 2 days, full days actually, on the loading an external file into the RAM in Proteus simulator and tonight, some minutes ago we reach the salvation conclusion. Now I can load any external file as long it is not very complicated because the editor is very old and is not that nice to edit with it, but it is doing an excellent job, and that is all that matters. I will still have to research into more modern .bin editors, so there is more to push. We have progress.