On Monday, February 17, 2003, at 08:35 PM, Kevin Stevens wrote: > On Mon, 17 Feb 2003, Dustin wrote: > >> Wallstreet. The limitation is for OS X only, AFAIK. OS 9 installation >> works fine in Classic mode though. >> >> -Dustin > > Since it's a limitation regarding what parts of the disk can be > accessed > by OpenBoot, I doubt the limitation is OS-specific. Also, installation > once any OS disk drivers are loaded probably wouldn't be a problem, > either. > > Perhaps someone more knowledgeable will respond, but I still think > you've > encountered an architecture limitation.
to begin with, Macs use OpenFirmware rather than OpenBoot. the difference is rather fine, but in essence, OpenBoot is the Sun-branded proprietary version of their own OpenFirmware property. as explained to me by someone at Apple... OpenFirmware has to bootstrap certain things in a specific order. enabling the ATA controller, the I/O controller, on up to actually loading the OS into RAM and finally executing code on the processor. when the OS loads is semi-arbitrary, and has to do with what the OS requires in order function, rather than hardware considerations. an OS that requires a protected memory scheme, for instance, has to load code in to the execution pipeline very early in the boot process. OS X requires this, OS 9 does not. for OS 9, it's just fine to wait until much later in the boot process to load any OS-specific code. on the 8GB-limited machines, the firmware itself can access data in the first 8GB without actually having to load the ATA controller code from the BootROM. why is all of this exposition important? loading the ATA controller code and initializing advanced features of the chip (and thus, allowing access to the disk beyond the 8GB limit) happens too late for the bootstrapper to still load OS X. it's NOT, however, too late to load OS 9. supposedly, on some machines this is less set-in-stone than on other machines... people have reported workarounds for some machines. -- G-Books is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Check our web site for refurbished PowerBooks | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> G-Books list info: <http://lowendmac.com/lists/g-books.html> --> 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/g-books%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
