---Let me guess: Jeff's been to college-and more than just a day!
Fluxstringer <[EMAIL PROTECTED]> wrote: > >>From: "Terry Mathews" <[EMAIL PROTECTED]> > >>Subject: Re: How to rate one's bus speed? > >>Date: Thu, 24 Jul 2003 22:58:27 -0400 > >> > >>> But I will bow to the experts. My machines must > run under different > >> > >>For whatever reason, all the processor cards you > tried must have utilized > >>the same or similar clock speeds. Believe it or > not, the processor card > >>tells the motherboard what clock speed to run at. > That's why most G3 and G4 > >>ZIF carrier cards have some sort of settings for > the user to configure. > > > >To elaborate a bit on what Terry wrote---he's > absolutely correct. > >The memory bus speed on the x500 and x600 (and > related clones) > >machines is set by the CPU card. > > > >There is no oscillator on the motherboard which > provides a > >memory/CPU bus clock. There's an oscillator > (33.3333) for the PCI > >bus, and one for the sound circuitry and one for > some of the other > >I/O, but none for the memory bus. > > > >Pins 9 through 14 in the CPU slot connector provide > the memory/CPU > >bus clock signals. Those signal originate on the > CPU card, go > >through pins 9 through 14 on the CPU connector and > tell the > >components on the motherboard what the bus speed is > for the CPU card > >that is installed. > > > >There are six of them because the signals are not > split. It's one > >clock signal per component. So one of them goes > to the memory > >controller chip (343S1190), one goes to the PCI > controller chip > >(343S0020) and I'm not sure where the other four > go. In the 9500 > >and 9600 one would go to the other PCI controller > chip. In the 7300 > >- 8600 one would go to the video controller chip > called > >CHAOS/Control. Two may go to the Data Path > controller (343S1141) but > >I'm not certain about that and I've never traced it > out. I'm > >pretty sure there is at least one and maybe two > extras that don't > >actually go anywhere. > > > >Apple originally intended this architecture to be > capable of > >supporting up to four "bridges" on the CPU bus. > That would mean > >four Bandit chips running twelve PCI slots, or > three bandit chips > >and one built in video, etc. But they never went > beyond two in > >any machine. > > > >Jeff Walther > > > Thanks, Jeff that's the clearest elucidation yet on > this subject. You > are an expert. > > > > > -- > Adrian > > -- > PCI-PowerMacs is sponsored by > <http://lowendmac.com/> and... > > Small Dog Electronics http://www.smalldog.com | > Refurbished Drives | > -- Sonnet & PowerLogix Upgrades - start at $169 | > & CDRWs on Sale! | > > Support Low End Mac > <http://lowendmac.com/lists/support.html> > > PCI-PowerMacs list info: > <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> > > Using a Mac? Free email & more at Applelinks! http://www.applelinks.com -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
