>> Does this mean that restarting and then holding down >> Cmd-Opt-Shift-Delete >> will not result in starting from one of the HFS+ partitions?
> Yes, that's exactly what that key combination does, forces a Mac to look for > a volume other than the internal boot drive to start up from. This has even > worked for me when trying to start up from a CD, on those rare occasions > that holding down the "C" key fails to work. You can use c-o-s-d (aka "DOCS") or the C key to boot from a different device, but not a different partition on the same device. For the long version of that, read on... Note the distinction between "drive" and "volume". A drive (aka "disk") is a physical device, while a volume is the filesystem contents of a logical partition (on some physical device). The four-finger startup combo tells the boot firmware to skip the internal drive and sequentially try other devices (really this means it won't look for a driver on the internal disk, which in some cases in the past could cause the internal partitions to disappear even once you'd booted an external drive). Clearly this means any partitions on that device will get skipped. The 'C' key originally meant "go straight to SCSI ID 3", which was the default place to find a CD drive. Nowadays it likely means "boot the master device on the secondary ATA controller", which is again usually a CD. As for boot order, I *think* it's in ascending SCSI ID order (but it might be descending, there's a lot of SCSI controller trivia mixed up in my head from the past twenty years ;). Originally the "internal drive" to skip meant SCSI device 0 - now it probably means the primary ATA controller. In troubleshooting disk problems, it's often useful to keep an idea of layering in your head (as with so many other computing issues, especially networking). So here we have: host controllers (SCSI, ATA, Firewire, USB) that talk to multiple targets storage devices and their media (entire hard disks, CDs, removables) device drivers that allow the OS to use the physical device disk partitions that create virtual smaller devices various filesystems (sets of directories and files, all within one partition) OS software stored in the filesystem. The Startup control panel or DOCS key combo lets you choose a device before any drivers are even loaded (without a driver the device can't actually be read, which means we don't even know what partitions exist yet). Once loaded from that device, the device driver will look in the partition table to find out which partition to boot, or perhaps read yet another key combo for a user choice - as with the FWB HDT driver (command-option-shift-e-N, where N is a partition number) or the option key on New World Macs. On newer Macs the Startup control panel mingles these two concepts, allowing you to choose both a device and a default partition (your choice is written to the partition table). In the boot process, the layers become available in order. That means it doesn't matter what kind of filesystem a partition contains as long as the driver can figure out how to boot it - HFS, HFS+, UFS, whatever. Of course, the OS software stored in the filesystem needs to be able to work with that type, or the boot won't get very far. But that's a whole other story. ;) You don't normally have to go very low on that impromptu chart unless you're erasing or repartitioning a disk. Normal operations, installing software (even the OS) and the like are all at the highest layer. Disk First Aid or Norton Utilities mostly work with filesystems (they use "directory damage" as a synonym for "filesystem corruption"), occasionally fixing partition table problems. The other stuff is generally hardware hacking. ;) -- Marc Sira | [EMAIL PROTECTED] If you can't play with words, what good are they? ---------- Duo/2400 List, The friendliest place on the Net! A listserv for users and fans of Mac subportables. FAQ at <http://www.themacintoshguy.com/lists/DuoListFAQ.shtml> Be sure to visit Mac2400! <http://www.sineware.com/mac2400> To unsubscribe, E-mail to: <[EMAIL PROTECTED]> To switch to the DIGEST mode, E-mail to <[EMAIL PROTECTED]> Need help from a real person? Try. <[EMAIL PROTECTED]> ---------- Dr. Bott | 10/100 Ethernet for your 2400 is finally here! MPC-100 | <http://www.drbott.com/prod/mpc100.html> RoadTools $30 PodiumPad available at Apple retail stores, $20 Traveler CoolPad at Staples. Both in white for iBooks at <http://roadtools.com> Midwest Mac Parts ][ <http://www.midwestmac.com> After-market parts for Macs. ][ 888-356-1104 ][ MacResQ Specials: LaCie SCSI CDR From $99! PowerBook 3400/200 Only $879! Norton AntiVirus 6 Only $19! We Stock PARTS! <http://www.macresq.com>
