Hi,

> > I have many Quadra 605 / Performa 475 machines. They are excellent,
> > overclock easily to 40 MHz, and now I've found a cheap source of 64 meg
> > SIMMs. Interested in learning more?

> I'll certainly bite.  I am interested in learning more.
> I thought 64mb SIMMs couldn't be used on nearly all 68K Macs
> (I have a little ring of Q800s, a 750 and an 840).

For starters, the 64 meg SIMMs work just fine in the 40 MHz Quadra 605 /
Performa 475 systems. I haven't tested them in any Q800 / Q650 yet, but
I'll report the status of that when I have a go.

They're physically small enough that there is no issue with installing
them while a heat sink is on the 68040 (of course), and they're CHEAP -
$less than $12.00 USD apiece!

This is how they are listed:
SNFP32U/064/F5V4K   64 MEG 16*32 4K REF APPLE/MAC 72 PIN SIMM

The place is Coast to Coast memory and you can find the listing here:
http://www.18004memory.com/category.asp?pagetoview=2&catid=9&subcatid=9

I only buy from them over the phone - their web site's credit card stuff
is a little wacky and I don't trust it. (1-800-4MEMORY)


> Please tell me (us) more.  Do you have a little HOW-TO
> so I can overclock my old Centris 650?
> I'd hazard a Q800 to 50 Mhz.  What do you think?
> How much (and under what environments) for the 64mb SIMMs?

All of my Quadra 650 / 800s run just fine at 40 MHz, but I've not had one
go up to 50. I have an 840AV that runs at 50 MHz, but the NuBus no longer
works, so I'm going to try 48 MHz, then 44 Mhz.

As soon as I can borrow a digital camera, I'll create a little HOW-TO with
pictures; in the meanwhile, check out:
http://homepage.mac.com/schrier/mhz.html

John Klos
Sixgirls Computing Labs