On Aug 15, 2011, at 9:57 PM, D. Fabel wrote: > Quick question for everyone. > > I was given a G3 Rev D (tray loader). I have retail discs (CDs) for both OS > 10.0 and 10.3. With the 10.0 disc I can change the "Start Up" disk to point > to the CD. With the 10.3 disc, I cannot. Any thoughts on what might be > happening here? >
Don't know...but holding down the 'C' keu while booting should force it to boot from either of them. > I've tried installing all the updates, but admit I am new to Mac and a little > unclear what is supposed to be happening (or what version I "should" have). > What I've found is the following: > > ROM Version $77D.45F6 > Boot ROM version 3.0.F2 > Mac OS Rom File version 8.7 > > Why is everything called a ROM? I'm confused and would appreciate > enlightenment! Three different things, all 'Read-Only Memory' and they're kind of connected. The following is is from very old memory and may be wrong on some of the details but the gist is correct, I believe. Boot ROM is what's stored in the boot sector of the disk. This is the information needed to get the Mac OS from turned off to started up from the hard drive. ROM Version $77D.45F6 is the stuff stored in the PRAM that contains very low level routines used by the Mac. Mostly it runs the very bare hardware level stuff. How the disk talks to the motherboard, etc. (this is the stuff that the drivers in the OS, .kexts in OS X System Extensions in the classic OS talk to, to use the hardware) Mac OS Rom File contains the Mac OS routines that used to be stored in actual chips on the motherboard, the original Mac OS Toolbox; starting with the B&W powermacs and the iMac this was stored as a disk file on the HDD instead of the ROM chips in the older systems. That makes it a LOT easier to update. -- Bruce Johnson "Wherever you go, there you are" B. Banzai, PhD -- You received this message because you are a member of the iMac Group, a group for those using Apple iMacs and eMacs. The list FAQ is at http://lowendmac.com/imac/list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/imaclist
