View Full Version : Rev A imac drive upgrade

08-18-2001, 01:57 PM
I have searched through your archives and have come across a topic from last year which I can no longer access.
I have a 20gb drive in my 6500 which I am going to get a larger one and want to put the 20gb in my old imac. I tried it to make sure that it would work and cannot get the imac to boot off the drive. I can start off OS cd and the drive appears, but when I try to boot off the hdd it puts up a message in the top left corner giving info on "imac firmware....." and giving like a command line request 0> and will only move on after I type 0 and then it asks for 1, 2, etc.
Is there a known drive compatibility problem with imacs and is there a way around it?

08-19-2001, 02:34 AM
No drive incompatibility, but there is a Mac OS incompatibility. You need to install an updated driver in that drive and install a new copy of Mac OS. It would probably be best to format the drive with Drive Setup and install clean.

The window you're getting thrown into is the Open Firmware. You probably ended up there because a compatible Mac OS ROM file wasn't present in the System Folder.

08-19-2001, 03:58 AM
The drive I have tried is split into trhee partitions, the third one had no system folder on it, so I installed OS9 from my upgrade CD, not the original imac cd, and it still would not let me in on the drive. Which driver do I need? I also have 9.1 update which could be installed - should I do that as well?

08-19-2001, 04:05 AM
Run Apple's Drive Setup (It's on your OS 9 CD) to update the driver. Select the drive in the window and then select Update Driver from the Functions menu.

Also, be sure to Unbless any System folder on the other partitions. You can do this by moving the System file into an empty folder in the System Folder (Effectively separating the System and Finder from each other).

Yes. Update it to 9.1 since it's likely you've already flashed the iMac's ROMs for 9.1.

[This message has been edited by lasvegas (edited 19 August 2001).]

08-19-2001, 01:06 PM
The drive has 9.1 installed with current driver installed and will still only start on the cd. The imac is a revision a - the topic from July 2000 indicates that someone else may have had a similar problem. Information would be appreciated.

hubba bubba
08-24-2001, 12:49 AM
try installing on the first partition. clean install.

08-27-2001, 08:56 PM
i encountered the same danged thing....and i don't remember how i worked around it.


i seem to recall making three partitions, and taking care to ensure that the first was under 8MB in size (this may be just a bG3 issue, but I think I had to do it in an iMac, too).

on the first partition, I installed MacOS9.1, w all updates. On the second, OSX, again w all updates.

I used Drive Setup 2.03 to initialize and partition the drive.

I'll check with spud to see if he remembers further details. I'm pretty sure he was involved, as well.


http://www.macgurus.com/ubb/batlogo.gif Batsignal invoked to spud!

08-28-2001, 01:41 AM
Jeezuus, magician partitioned a drive? What are we coming to? And it was an iMac that made him do it? And not an 8 drive 144GB raid Burly? http://macgurus.com/infopop/emoticons/icon_redface.gif k

08-29-2001, 11:27 AM
i remember clearly that this imac job was a long head-aching job, although i did master ripping opening an imac in under 4.6 seconds...

if you haven't done so already update the firmware. you have to follow the instructions on the os cd(it may be the imac software install/restore cd.). it calls for you to hold in the "programmer's switch" which is the second of the two little holes near the usb ports(not the restart button). then you have to wait for the elongated chime then you can release the button and the computer boots as normal. make SURE that the paper clip or whatever you are using to hold in the button is thin enough to fit all the way into the hole. and the chime is very noticably different. after that you need to boot of the os 9.1 cd and do a clean install of the os on whichever drive partitions you need to. that's all i can remember...if you encounter any problems give us a....post. best of luck.


- Spud -
"We clean the basement
of Hardware Heaven...
and like it!"

08-31-2001, 02:47 PM
yeah....that iMac belonged to my brother-in-law....he wanted a phat drive for his MP3 collection (which is excellent, btw...) and more SDRAM for Unreal.....that stupid drive kicked my butt. LIke I said, we finally figured it out, but i just don't remember what the heck we did. We'll be back in iMac hell again here shortly, as my son has one that is getting an old NewerTech upgrade, memory and a bigger drive....if this thread is still active when we get into it, I'll post once i remember what to do.

k, i think i'm getting older than you and Louie. My memory is worse than ever. (but I still kick butt in the sack).


hubba bubba
09-12-2001, 03:31 PM
I ran into this after installing OS 9.1/9.2.1 and OS X on a 30Gb drive in an original iMac. Put OS X on the first partition (of 4GB), then copied my customer's 9.1 install and data over ethernet. Restarted in OS X no problem, restarted into 9 and got the same open firmware type message. Reinstalled, reset PRAM, logicboard, etc., no luck. Defragmented the drive, worked fine. Apparently the network copy had put the system folder all over the drive. OS X needs to be on the first 8GB, but apparently the older iMacs and G3s have the same sort of problem with new large hard drives and the Mac OS. Once the OS was defragmented to the beginning of the second partition (still within the first 8GB) it booted into either OS with no trouble.

09-17-2001, 03:54 PM
that is interesting....it almost sounds like the same sort of thing we encountered (and Apple documented) in Beige G3: use volume partition sizes smaller than 8GB (like 7.85MB or so) and install your OS onto the first partition.

09-21-2001, 03:58 AM
Hi, sorry about the delay in responding, a few things been happening recently! Even here in the UK.
Ok, this is how I resolved it, and maybe someone can tell me why this should have been necessary.
I have two versions of OS9, one that I bought in the US 18months ago, and one that I bought in the UK seven months ago.
I have several machines running OS 9, 7300, 6500, PB G3 500 and the imac. I wanted them all running on the same version of the OS, which is why I bought the UK version - my Powerbook will only run with the UK original supplied with it. I installed the UK 9 in the imac, and as earlier noted, it did not want to know. So thinking logically, I installed the US version, which had been running in the imac before the HD change, and lo and behold, NO PROBLEM! What is going on here?
Can anyone suggest a reason - has the ROM become "infected" or something?
While this is no longer a problem, it is frustrating and I wouuld like to know why.