Subject: Re: Q840AV chip slips right into Q800, right?
To: John Klos <email@example.com>
From: Ken Hughes <firstname.lastname@example.org>
Date: 11/24/2001 00:40:22
Mr. Schabert and Mr. Klos,
Thank you for your generous responses.
I am embarassed again to be reminded of the classic usenet posting advice.
Think!! and never post late at night when tired.
Of course, what I really mean is increasing the clock rate (and I will
follow your advices).
Anybody on this list in the Vancouver, British Columbia area?
Any ethernet cards or transceiver cables for sale out there?
Gonna turn my Quadras into real computers.
Best to all,
On Fri, 23 Nov 2001, John Klos wrote:
> > >Would it not be a good idea to swap a Q840AV chip with the Q800?
> > >The Q840AV also has 4 VRAM chips which I presume are the VR256K SIMMS,
> > >but I'll check. [No Q840AV ever got 4 512K VRAM chips, or other, did it?]
> > OK, I think that you're "mixing metaphors" here. To switch chips
> > would mean to pull the 80Mhz 68040 out of the 840AV's motherboard and
> > shove it into the 800's motherboard, trying to essentially overclock
> > the machine. The "chip" has no VRAM or VRAM sockets...what it sounds
> > like you're trying to do is swap *motherboards*, essentially using
> > the 800's case and power supply to drive a Quadra 840AV.
> To expand on this a little, every Quadra 650 / 800 I've ever set up runs
> fine at 40 MHz. The Quadra 650 / 800s use a 33 MHz 68040 generally with a
> manufacture date newer than the middle of 1993, and run much cooler than,
> say, a 33 MHz 68040 from a Quadra 950, which are generally older. The
> older chips may not work at 40 MHz, but every newer one I've tried runs
> fine at 40 MHz.
> This includes all seven of my Quadra 605 / Performa 475 motherboards which
> have newer 25 and 33 MHz '040s running at 40 MHz.
> In order to do this on a Quadra 650 / 800, find the oscillator next to the
> innermost NuBus slot (16.667 MHz) and replace it with a 20 MHz oscillator.
> If you have a Quadra 840AV, it can usually be safely overclocked to 50
> MHz. Don't remember the location of the oscillator on that. But if you
> don't have a case, a milk crate with a bunch of zip ties will do. I have
> two Quadras set up this way.
> No matter what you overclock, though, make sure you take off the heat
> sink, wipe off the old and usually dry compound and put on new heat sink
> compound. Keeping the chips cool is important for stability.
> Sixgirls Computing Labs
Why "Sixgirls"? What do they do, or signify? Where did you find them?