In the posted image, it appears that you measured UK14 pin 2 1Hz with the meter in AC mode. Switch to DC voltage measurement and measure again. This is actually a digital signal. Make sure the Mac's power is on. Then measure that same signal at UD11 pin 43. Make sure you are gently touching the...
The performance portion of the code is a unrolled loop that copies 32 bytes per loop. So, basically, nothing else is as impactful on the result as this portion of code.
The addition operation is used to verify that memory is valid. The buffer has been preloaded with an incrementing value where...
Agreed. That wouldn't surprise me. That's my big caveat to all of this. I'm using a period-correct compiler (Metrowerks CodeWarrior 11 Gold) with pure C code that is not specifically tailored for a PowerPC processor. I am positive that if I wrote this code differently and chose 603 instruction...
I reran the tests on the 6200 603 @ 75 MHz and got basically the same results. So, I didn't modify the spreadsheet for those rows.
I then ran it on a 6300 603e @ 100 MHz board (same chassis). Dramatically better, but still doesn't beat the 68040 internal cache for this particular test...
Well, I don't know if this is going to cause a flame war. But here goes...
I tested using MacOS 8.1. Same exact drive, chassis, etc for all tests. Only the motherboard was swapped. I did not modify your application. For consistency, I used the compiled versions exactly as you uploaded earlier...
I'm unable to check that any time soon, as I finished fixing my last Portable earlier this week. It's all put back together and they are such a pain to disassemble. If I have reason to open one, I'll check for you.
That being said, measuring in circuit values is difficult as there are so many...
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