<div dir="ltr">I noticed the thermals aren't that bad at the rated speed. The case itself is pretty open and well laid out for passive cooling, and I wonder how destructive it would be to remove the current stacked pancakes heat spreader and put something bigger in. I also noticed that the CPU itself is labeled -70, but reported by the system to be running at 60Mhz. Not sure if that label is speed rating, it's a sticker and not printed on the heat spreader like it is for the -110.<div><br><div>Romain you're likely right that a drop-in might not work out of the box unless the clock multiplication is entirely internal. I'll look at what clocks exist on the board.</div><div><a href="https://datasheets.chipdb.org/Sun/microSparcII-STP1012.pdf">https://datasheets.chipdb.org/Sun/microSparcII-STP1012.pdf</a> seems to have all the info I'd need. It's a bit weird that the system clock is pinned and divided down for the bus, I'm used to bus speed being the guiding factor and the multiplier determining the system clock.</div></div><div><br></div><div>For the power side there's a DC/DC plug-in/replaceable component that could presumably be beefed up.</div><div><br></div><div>Dan.</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sun, Nov 9, 2025 at 12:16\u202fAM Romain Dolbeau <<a href="mailto:romain@dolbeau.org">romain@dolbeau.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Le dim. 9 nov. 2025 à 03:46, Dan Moisa via rescue <<a href="mailto:rescue@sunhelp.org" target="_blank">rescue@sunhelp.org</a>> a écrit :<br>
> Speaking of Voyager, can I take a microsparc-II@110Mhz out of a 5 or similar and substitute the @70 it comes with? So far I'm led to believe that yes.<br>
<br>
What you need to do depends on how the MicroSPARC II is wired.<br>
Presumably, it is using the internal PLL, so:<br>
* you need to change the clock supplied to the CPU to whatever you<br>
want to run it at;<br>
* you need to check what that clock is also feeding to make sure<br>
you're not overclocking unwanted components;<br>
* you need to change the input to the PLL divider (pins DIV_CNTL[1:0])<br>
so that the SBus is not overclocked. I assume it is 1/3 for a 70 MHz<br>
MicroSPARC II, you would need at least 1/4 up to 100 MHz (the voyage<br>
can probably take the SBus moving from 23.333 to 25 MHz), and 1/5 over<br>
100 MHz.<br>
* whatever else that might be needed<br>
<br>
Both then as Andrew said, power/thermal are going to be the problem.<br>
They're unlikely to be dimensioned for +50% on the CPU.<br>
<br>
Cordially,<br>
<br>
-- <br>
Romain Dolbeau<br>
</blockquote></div>