exxos blog - random goings on

[rubber_jonnie]

Next I need to try and work out where I got to with the RTC boards...

I thought you had a board designed and had some PCBs to make up?

[exxos]

I thought you had a board designed and had some PCBs to make up?

yes, I posted updating the other thread... https://www.exxosforum.co.uk/forum/viewt ... 587#p22587

So far, I tried a couple new boards which did not work, so tried the original board with the smaller RTC board plugged in, that worked, so I tried a different chip in that board, and it did not work, so I put the working chip in one of the new boards I built today, did not work, so I put that chip back in the original one which worked, and it still does not work.

I cannot find the board I built up a few weeks ago, so I have not actually got a working board at the moment it seems

[exxos]

So as usual, nothing is ever straightforward... with the RTC.. If I put my finger on certain PCB tracks on the PCB, the floppy drive either goes not, or it goes to desktop without showing the floppy icons so I think the RTC board some reason is loading the bus just enough for it to boot but but not run the RTC at all... So I will try adding some pullups on the board, but really I do not want to spend the next six weeks debugging the Atari motherboard's again over another stupid full

[exxos]

The pull-up resistors solved the odd stability issue, but the RTC still isn't working

I found my initial test board, it was inside one of the 3-D cases I was printing got that in, and it works fine. I also found the original FMCII cartridge that also works fine.

So I took the chip out of my own board which I knew was working (the 3D case one) , and put the chip in one of my previous test boards ( the one iwth the smaller RTC board plugged in) , which was working earlier, and that did not work again with basically a known good chip.. I put the chip back in the other board which I had found just (the 3D case one) , and that one also stopped working also

The only thing I could possibly think which may have caused a issue was I forgot to take the battery out of the board before changing the chips. I wouldn't have thought that would have killed it, but other than placing the chip in a socket is somehow killing them, I really cannot think of any other way the chips are getting killed.

So I will order some more chips, replace the chip in the test board which I was using for the 3-D case is, as I know that board should be okay, so changing the chip should make that work again... Then try another chip in the socket, and if that one dies, remove the socket and solder the chip direct to the board...

But if the chips are going to continuously get killed, I will probably just give up on the project, as these chips are like £14 a pop! And I've killed a handful of them already

EDIT: Thread carried on (and solved) over here https://www.exxosforum.co.uk/forum/viewt ... =30#p22627

[exxos]

Audio jack holes are in the wrong place, but not important initially

Now to find my monitor...

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[PhilC]

Looking promising.

[exxos]

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MONO

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COLOUR

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COLOUR AFTER ADJUSTING THE IMPOSSIBLE TO ADJUST POTS

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[PhilC]

Looks great. Only suggestion I would make whilst seeing it in situ would be to change the jumper location to above the monitor socket perhaps?

[exxos]

Looks great. Only suggestion I would make whilst seeing it in situ would be to change the jumper location to above the monitor socket perhaps?

Yeah, I was in two minds When designing it where to put it, but I went with compact on this version, but I might move it above like you say as it is a bit hard to get at where it is, but how often would people change it anyway..

[PhilC]

Looks great. Only suggestion I would make whilst seeing it in situ would be to change the jumper location to above the monitor socket perhaps?

Yeah, I was in two minds When designing it where to put it, but I went with compact on this version, but I might move it above like you say as it is a bit hard to get at where it is, but how often would people change it anyway..

mines stuck on colour mode all the time, so fair point.