How can I reinstall OS9 on Graphite iMac DV SE 400?

I'm more than willing to help 3DMonkey, but I'm quite certain Apple does not consider OS 9 public domain. So emailing it would infringe upon their copyright and they can afford to pay their attorneys more than I could mine. Besides, I don't believe it would be as simple as copying it to your HD anyway. The installer probably does more than copy files, though I'm not sure what. Probably modifies the boot blocks or something.

I will check where the folder resides but I'm reasonably sure it's at the root level. Knowing its location probably won't help though.

OS 9 retail install discs show up from time to time on eBay, though I can't find any at the moment. Amazon Marketplace has them at absurd prices. So does this vendor: http://hardcoremac.stores.yahoo.net/

I'll let you know what I find out with my iMac.

If you're looking just for a retail OS 9 disc, you can also usually find them via Craigslist, depending on which city you live in. Another possible source is to join Freecycle.org and post a Wanted request for a retail OS 9 disc. Everything on Freecycle must be free, per the member requirements.

OK 3DMonkey, here is what I determined:

You can boot the DV SE with the OS 9 retail disk by holding the "c" key at startup. Apparently, the technique of using the option key (which is normal for OS X) won't recognize the optical drive as a startup device. Apparently my recollection of an inability to boot an OS 9 formatted CD with updated iMac firmware is not correct.

As I wrote earlier, I do not know if the "c" key technique will work if the optical drive has been replaced - mine is original so it works.

Once you install OS X and the drivers for Classic/OS 9 you can use the Option key which enables you to choose the OS 9 System Folder on the HD. Installing OS 9 is painfully slow as it wants to check the entire hard disk for integrity at every step. The iMac originally came with a 30 or 40 GB HD but I upgraded it to the largest one possible 128 GB. The OS 9 programmers probably never thought they would have to integrity-check such an enormous disk.

Here is the root level directory on mine

Last login: Wed Feb 8 20:25:34 on console

Welcome to Darwin!

Johns-iMac:~ john$ cd /

Johns-iMac:/ john$ ls -l

total 1611746

-rwxr-xr-x 1 root john 925696 Feb 8 18:31 AppleShare PDS

drwxrwxr-x 87 root admin 2958 Feb 8 20:14 Applications

drwxr-xr-x 15 root john 510 May 31 2010 Applications (Mac OS 9)

drwxr-xr-x 2 john john 68 Feb 8 19:30 Cleanup At Startup

drwx------ 8 john admin 272 Jul 18 2011 Desktop

lrwxr-xr-x 1 john john 15 Nov 6 2008 Desktop (Mac OS 9) -> /Desktop Folder

drwxrwxrwx 13 root staff 442 May 31 2010 Desktop Folder

-rwxr-xr-x 1 root john 0 Aug 28 2000 DesktopPrinters DB

drwxr-xr-x 12 root john 408 Dec 4 2005 Documents

drwxrwxr-t 42 root admin 1428 Feb 8 19:16 Library

drwxr-xr-x 1 root wheel 512 Feb 8 20:25 Network

drwxr-xr-x 4 root wheel 136 Feb 8 20:23 System

drwxrwxrwx 51 root admin 1734 Feb 8 18:31 System Folder

drwxrwxr-t 8 root admin 272 Feb 8 19:14 Users

-rwxr-xr-x 1 john john 815792128 Feb 8 19:30 VM Storage

drwxrwxrwt 6 root admin 204 Feb 8 20:24 Volumes

drwxrwxrwt 2 root wheel 68 Apr 22 2001 Volumes (Mac OS 9)

drwxr-xr-x 4 root john 136 Apr 3 2005 automount

drwxr-xr-x 40 root wheel 1360 Feb 8 20:12 bin

drwxrwxr-t 2 root admin 68 Apr 3 2005 cores

lrwxr-xr-x 1 john john 13 Nov 6 2008 cores (Mac OS 9) -> private/cores

dr-xr-xr-x 2 root wheel 512 Feb 8 20:23 dev

lrwxr-xr-x 1 root admin 11 Feb 8 18:49 etc -> private/etc

lrwxr-xr-x 1 john john 11 Nov 6 2008 etc (Mac OS 9) -> private/etc

lrwxr-xr-x 1 root admin 9 Feb 8 20:23 mach -> /mach.sym

-r--r--r-- 1 root admin 604360 Feb 8 20:23 mach.sym

-rw-r--r-- 1 root wheel 4352200 Oct 10 2007 mach_kernel

drwxr-xr-x 6 root wheel 204 Feb 8 20:23 private

drwxr-xr-x 63 root wheel 2142 Feb 8 20:13 sbin

lrwxr-xr-x 1 root admin 11 Feb 8 18:52 tmp -> private/tmp

lrwxr-xr-x 1 john john 11 Nov 6 2008 tmp (Mac OS 9) -> private/tmp

drwxr-xr-x 8 root wheel 272 Mar 28 2005 usr

lrwxr-xr-x 1 root admin 11 Feb 8 18:52 var -> private/var

lrwxr-xr-x 1 john john 11 Nov 6 2008 var (Mac OS 9) -> private/var

Johns-iMac:/ john$

The OS 9 System Folder is called just, that whereas the OS X System folder is called "System". Most of the other files are OS X specific.

As you can see there are a lot of other files that relate to OS 9, not just the "System Folder" contents. So it's not as simple as just copying the folder - that alone would not be sufficient to boot OS 9. Furthermore, the HD boot blocks are not determinable from the above, and I think that is what you need to boot OS 9. I believe that can only be accomplished with the retail distribution CD-ROM.

Let me know if this helps, or if there is anything else you want me to do with the DV SE before I put it back into storage.

Here is a screenshot of the machine booted in OS 9:

and another of a circa 1987 program that I originally bought for my SE/30, running on the iMac:

Yes it still works, even if Compuserve isn't around any more 🙂

Hi everybody,

I got exactly the same trouble, after ten or more installations I finally solved it whith the following process :

Step 0 : formating the HD using disk tools on mac OS X v10.2 install disk, be sure to check os 9 support

Step 1 : mac os x v10.2 installed from original retrail disc

Step 2 : then I had exactly the same issue whith classic "can't start form a copy"

Step 3 : reboot on os x 10.2

Step 4 : then updated the os 9 support from an original grey mac os 9 install disk which came with a mac mini (before step 1, the iMac was not able to boot on this disk)

The os 9 is now version 9.2.2 and the rom version is vFU1-10.2.1, the iMac fires up on OS 9 !!