FYI….
The last Paragon I worked on had about the same issues. I traced the problem to
two common CD4000 series ICs in the rear left corner of the mother board. It’s
been so long that I don’t remember the number of the chips. They are common off
the shelf parts.
That cured the goofy logic board problem.
MIke, WB8VGE
Mike Bryce
prosolar@sssnet.com
> On Sep 14, 2016, at 12:42 PM, Louis Ciotti <lciotti1@gmail.com> wrote:
>
> Fresh battery is in place.
>
> I really thing it is either a dead CPU or the EEPROM got scrambled. I
> found a source for a low cost CPU so I ordered it.
>
> When looking at the signals with the O'scope, the IRQ line does not look
> right:
>
> https://goo.gl/photos/6ohJcT8Lu4qrSsVp9
>
> All the other logic line look nice with out the finky ripple on the lines.
> If I remove the CPU this line goes to nice smooth a logic high, which is
> what ll the digital line with a logic high on it look like.
>
> If I swap the CPU and that does not cure it, I am going to say the EEPROM
> is dead.
>
> I wonder if TenTec would have the source code for the 6805 assembly code,
> or the EPROM image stored somehwere and I can re-burn since it looks like I
> can still get the eprom as well, I just would need to get a burner.
>
>
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