Quadra 605 build log

[zigzagjoe]

I've had the same experience. I've wondered if it has something to do with the tolerances of the RAM and/or VRAM I'm using.

If the machine isn't crashing, just not going faster, then you've hit the limits of the PLL chip. When they run out of overhead they just stop increasing in frequency.

 

[Fizzbinn]

If the machine isn't crashing, just not going faster, then you've hit the limits of the PLL chip. When they run out of overhead they just stop increasing in frequency.

This is the stock MC88920? Replacing with MC88916 like this would be need go hit higher speeds?

MOTOROLA MC88916DW80 SOP-20 IC DRIVER CLK PLL 80MHZ 20-SOIC | eBay

◆If there are no special circumstances, your product will not be delayed in arrival.

www.ebay.com

Upgrade MC88920 to MC88916 for LC475/P475/Q605 (advanced soldering)

In the Overclock LC475/P475/Q605 without soldering or spicy-o-clock thread I learned that LC475 can be pushed to the limit of the MC88920 by software, but to exceed this limit MC88920 need to be replaced by MC88916. There were some questions about availability and sources that can be discussed here.

68kmla.org

 

[zigzagjoe]

This is the stock MC88920? Replacing with MC88916 like this would be need go hit higher speeds?

MOTOROLA MC88916DW80 SOP-20 IC DRIVER CLK PLL 80MHZ 20-SOIC | eBay

◆If there are no special circumstances, your product will not be delayed in arrival.

www.ebay.com

Yes, to both counts.

 

[65a]

Well, I got the clock chip in nicely (please ignore the fact that tinfoil is insufficient to protect the plastics perfectly in this area). I can actually clock to 45mhz now, but I get a bus error at 50mhz. Haven't investigated that too much (or cleaned the flux off yet).

 

[Phipli]

Well, I got the clock chip in nicely (please ignore the fact that tinfoil is insufficient to protect the plastics perfectly in this area). I can actually clock to 45mhz now, but I get a bus error at 50mhz. Haven't investigated that too much (or cleaned the flux off yet).

View attachment 98627

You'll want to move R96 to the R95 position. It won't be stable without.