On Fri, Dec 30, 2016 at 6:53 PM, Josh Dersch wrote:
> Just to bring some closure to this old thread, I finally picked up a
> working TMS9980 cpu chip (after getting one faulty one off of eBay -- it
> was even more dead than the one it was replacing). And it appears to work
>
On Fri, Dec 30, 2016 at 7:53 PM, Josh Dersch wrote:
> Just to bring some closure to this old thread, I finally picked up a
> working TMS9980 cpu chip (after getting one faulty one off of eBay -- it
> was even more dead than the one it was replacing). And it appears to work
>
Just to bring some closure to this old thread, I finally picked up a
working TMS9980 cpu chip (after getting one faulty one off of eBay -- it
was even more dead than the one it was replacing). And it appears to work
properly in the 990/189 board, with the 9.3V supplied on the CPU socket.
Thanks,
9.3V might actually work fine for a TMS9980, even though it's below spec.
It's not going to damage the part, so it may be worth a try before
modifying the board for 12V to the CPU socket.
In NMOS digital parts that predate depletion loads, Vdd needs to be
significantly higher than the most
Hi all --
Got myself a TI-990/189 single-board computer based around the TMS9980
microprocessor (actually, a variant of it, the MP9529, which apparently
differs only in that it has a lower maximum clock and only requires Vdd
of 9.3V or so...)
It was advertised as "it looks like it's