Date: Fri, 30 Apr 2004 22:34:19 -0700 (PDT) From: Gregg Eshelman <[EMAIL PROTECTED]> Subject: Re: Daystar Turbo 040/40 - overclocked? In-Reply-To: <[EMAIL PROTECTED]>
--- Mark Benson <[EMAIL PROTECTED]> wrote:
Looking at John's post and looking again at my Turbo040 I really can't see it having been re-soldered. There are a lot of SMT components around it that have not been so much as even disturbed. There are no burn marks or signs of heat. If it was a non-factory job they made one hell of a tidy job of it :)
OTOH, toward the end of Turbo 601 production, Daystar was underclocking 100Mhz chips to 66Mhz and 110Mhz chips to 100Mhz.
I'm sorry this is two months late. I was busy with finals when these original messages went out.
While there are some Turbo601/66s with 100 MHz chips installed, the Turbo601 does not tolerate traditional overclocking at all. That is, you can't just replace the 33 MHz oscillator with a 50 MHz oscillator, or even a 35 MHz oscillator. You must change the PPC601 from clock doubling (33.3333 MHz bus speed, 66.6666 MHz CPU speed) to clock tripling (33.3333 MHz bus speed, 100 MHz CPU speed).
The one time I did it, the PPC601/66 CPU on my card ran okay at up to 96 MHz. I didn't need a card with a PPC601/100 CPU.
To change a Turbo601/66 into a Turbo601/100 it is necessary to move about eleven resistors and to install a 44 pin clock generator chip, the ICS9178. I don't think the ICS9178 is available any longer, but it is possible that ICS makes something pin compatible.
They can also be salvaged off of 8100/100 and 8100/110 or PowerComputing Power 100 or Power 120, but that kills the donor.
I have an article about the procedure on Marc Schrier's Clock Chipping Home Page. I would ignore the parts which are detailed soldering procedures. I've found better ways of doing most of the soldering that I describe in the article.
Jeff Walther
-- Vintage Macs is sponsored by <http://lowendmac.com/> and...
Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! |
Support Low End Mac <http://lowendmac.com/lists/support.html>
Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/>
Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
