Comments on: What's required for a Mac OS 8 CD to be bootable?

Question: What's required for a Mac OS 8 CD to be bootable?

Grinder — Fri, 13 Jan 2006 08:51:44 -0800

What's required for a Mac OS 8 CD to be bootable?

Some time ago, I bought a G3 Kanga PowerBook. It was cheap and seemed to be a good deal. It turned out to be a refurbished machine, but that's not the problem. It didn't come with an original Mac OS installer but with a disk that the vendor had burnt. The disk has the installer for Mac OS 8.5 on it but it won't boot.

As far as I understand, all that needs to be on a Mac OS so that it's bootable is a System Folder containing the necessary files like the Finder. All that is here but the disk still doesn't work.

Are there magic or hidden files that need to be present, like an MS-DOS boot disk?

By: bonaldi

bonaldi — Fri, 13 Jan 2006 08:59:50 -0800

it needs to be blessed, which you can't do once it's burnt.

By: chunking express

chunking express — Fri, 13 Jan 2006 09:01:50 -0800

When you burn it, you need to say that it's a bootable CD. You can probably copy the CD to an external HD and boot off it though. That might be worth a shot. You may also be able to burn it again, but this time mark that it's to be used to boot.

By: kindall

kindall — Fri, 13 Jan 2006 09:34:18 -0800

"Blessing" the system folder, by the way, consists of altering the boot block so that it knows the ID of the system folder. The reason this is necessary is that the system folder on a "classic" Mac OS disk needn't be called "System Folder." It might be named in another language besides English, for example. So the bootloader was designed not to care what it's called but rather to locate it by ID. The easiest way to bless a system folder using "classic" Mac OS is to move the Finder out of it, then back in -- the running Finder will say "ah, here is a Finder and a System file in the same folder, must be the system folder" and bless it. Mac OS X has a bless command-line tool that can do the blessing. When burning a CD, most burn software will either automatically find the system folder and alter the boot blocks on the resulting CD accordingly, or else there is a checkbox to make it do this (this is how Toast does it).

By: Grinder

Grinder — Fri, 13 Jan 2006 09:42:35 -0800

So if I copy the files to a hard disk, copy them onto a blank CD and take the Finder out of the System Folder and then put it back in, it should work OK?

Can I do this on a Mac OS X machine? The only CD burner I have easy access to is running X, but I can get access to one on a machine running Mac OS 9 if needs be.

By: chunking express

chunking express — Fri, 13 Jan 2006 11:09:24 -0800

I think you'd need to do this under Mac OS 9. It was an option when you burnt CDs with Toast. I'm not sure if you can still burn pre-OSX bootable CDs with the new version of Toast. I'm pretty sure you can't using the Finder in OS X. If you have an external HD, I think installing from that might be easiest.

By: kindall

kindall — Fri, 13 Jan 2006 11:09:27 -0800

Hmmm. Not 100% sure if that'll work with a disk image (which is what you're doing when you "copy them to a blank CD") or with Mac OS X (that's probably the more important consideration, as Mac OS X wants the System folder to be named "System"). On Mac OS X I'd try the command-line tool, bless -- see "man bless" for details.

By: Grinder

Grinder — Fri, 13 Jan 2006 12:55:38 -0800

What I want to do (but didn't make clear originally) is to have a bootable installer CD to hand in case anything happens to the PB HD. (At the moment it's working fine.)

This PB won't run X so it will have to be a Mac OS 8 disk. I'll try it on X and if that fails, I'll get to the OS 9 machine when I can.

I don't have access to Toast. Is that liable to be a problem?

Thanks to everyone for the helpful answers.

By: neuron

neuron — Fri, 13 Jan 2006 20:00:06 -0800

LowEndMac has a lot of info and resources for users of older macs. The maillists are good. There's one for G-Books, and i think another for legacy OS versions.

By: kindall

kindall — Fri, 13 Jan 2006 21:25:04 -0800

I don't have access to Toast. Is that liable to be a problem?

Nah, if you can bless the system folder on the disk image of the CD before you burn it, which you should be able to using the command line "bless" if not the Finder, it should work fine.

By: Grinder

Grinder — Sat, 14 Jan 2006 01:17:38 -0800

Thanks again. I'll give it a go.

By: joeclark

joeclark — Sat, 14 Jan 2006 15:33:46 -0800

You should try to upgrade it to OS 9.

By: chunking express

chunking express — Mon, 16 Jan 2006 09:28:50 -0800

I would agree. OS 9 was really amazing.