> <snip> > > The multiplier on the FX is "hot" switchable and can be controlled by > registers in the CPU. This means that after the CPU is turned on, > you could adjust the multiplier in the 750FX using software, assuming > someone wrote a utility to do this. One of Apple's utilities would > write to the register in question, but when folks started using it to > over-clock the iBook (the latest iBook uses the 750FX) Apple pulled > the utility and replaced it with a version that won't write to the > register in question. > > If someone can identify the manufacturer and model number of the pin > grid array and plastic matrix on the bottom of ZIF CPU modules, I'll > take a hack at building a 750FX board once I finish a couple of other > projects... > > Jeff Walther >
Now that you mention it, I am wondering why no one ever made an accelerator for these machines with RAM onboard it. You know, a memory controller of some sort and a couple of PC133 or better yet, PC2100 DIMM slot on it. That would be a screamer, as then the only mobo access would be for PCI and general I/O as opposed to getting all the memory from the mobo as well as the aforementioned PCI etc. Like a Cyberstorm or a Warp Engine, these accelerators had their own RAM which was many times faster than the slow interface to the slow mobo RAM on the Amigas themselves. Of course, the RAM speed isn't too bad on the Mac clones but if the RAM were local, things would get pretty interesting in terms of benchmarks between one of these boxes with such an accelerator on it, and say last year's new Macs.. AGP specific disciplines excepted of course ;-) The cyberstorm PPC had three clocks on it, and three oscillators. One was the system clock, which controlled the motherboard interface and the SCSI on the card. One was for the 68060 CPU's clock and the third was for the PPC clock. So the PPC could be overclocked independently of everything else. Some aspects of this dual processor board were kind of a nightmare, but the asynchronous clocks of the accelerator card/SCSI/Memory and each CPU was pretty neat-o. Phase 5, who also made the Maccelerate series of cards, were going to come out with a next-gen PPC accelerator card with PC133 memory and so on, but as with most things Amiga, they took a bunch of pre-paid pre-orders then went bankrupt :-( Bolton -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.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/supermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
