Recent content by David Cook

I like his initials on the memo so you could tell it wasn't just anyone with a Mac pranking employees.

Good story! Keep them coming.

LOL

This isn't an LC, but this is my favorite "replacement label" in my collection. I laugh every time I pass it.

There's something I like about this replacement label.

Ahh. That makes a lot of sense.

I think you're right. It should be 68030. Good catch.

Nope. Sorry. This is an oscilloscope. Don't know what I was thinking. Ignore this part.

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...

According to me, 33 MHz. According to Apple and Motorola marketing department 66 MHz.

Also, the dropoff at 256KB is more noticeable (although gradual for some reason) with the larger graph.

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...

Good catch. My typo. 6200 My thoughts exactly. I'm going to load it up again today and check everything.