2026 PowerPC Challenge, is it happening?

[Trash80toG4]

Day 21

I received my DSO-152 from Temu and have yet to learn it. I set out to try to find the fan speed signaling on the G5Q. I was ramping up the temps by running benchmarks.
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Great project, following closely.

Very much interested in your learning curve as you gain experience with this scope. I'm looking into a bit more capable, medium range scopes for my electronics exploration, to keep this thread clean:

https://tinkerdifferent.com/threads/mid-budget-oscilloscopes-150-325-range-suggestions.4996/

Amazon.com

 

[phunguss]

Day 22

I received my DSO-152 mini digital oscilloscope and had to watch a few online videos on how to properly use it. I connected to my G5 Quad with some needle probe adapters for my multimeter and the alligator clips on the DSO. Reading the Tach line pin 3 on the LCS.

Running through various benchmarks to get the CPUs hot and the pumps ramped up to decode the signals.

Nothing like running 10.4 with classic support and OS9 benchmarks!

Even the old CineBench 2003 for early osX

My best guess on the 12pin G5 Quad LCS is this:
1. V+ (1) 12v (no waveform detected, definitely not a PWM signal)
2. V+ (2) 12v
3. Tach (1) 3.3vpp
4. Tach (2) 3.3vpp
5. Vspeed (1) analog 0-12v, 3v at idle, 12v at max loads
6. Vspeed (2) analog 0-12v, 3v at idle, 12v at max loads
7. GND
8. GND
9. NC
10. NC
11. GND
12. NC

So it looks like using a standard 12V 4pin PWM computer fan will require converting 0-12v analog pin 5/6 to a 5v PWM driver.