"Bus error" bomb screen when trying to boot Mac OS 9.1 or later on a Power Macintosh G3 Minitower

[LeoI07]

I've been trying to get the latest version of Mac OS 9 (9.2.2) working on my beige Power Macintosh G3 (Minitower 266 MHz). However, there's an issue I've been encountering with all versions from 9.1 onward. The OS won't boot. The "Starting Up..." progress bar gets about a tenth of the way full, but then it throws a bomb screen error saying "bus error".

Sean from Action Retro got the same error with his G3 Desktop, and he was able to fix it by reseating the cards. I tried reseating the PCI cards, the I/O card, and the RAM modules, but that didn't fix the issue (although maybe it's because I always smack the side access panel quite hard to get it fully shut).

I can tell that there's some hardware issue with my G3 that prevents it from running later versions of OS 9 (although OS X 10.2.8 works just fine), and I know I'm not the only one who experienced this, since the sticker that was on the computer when I bought it said it ran OS 9.0 and not anything later, although maybe they didn't have any install media for later OS 9 versions.

If anyone knows how to fix this bus error, please let me know.

 

[bunnspecial]

1. Does it happen booting extensions off? (hold shift until the splash screen appears)

2. You said you'd re-seated RAM. What does your RAM make-up look like? These can be funny about RAM sometimes, especially the Rev. A versions. You might try just booting with one stick installed, and if it persists try each of the different sticks you have.

 

[Project Alice]

I've been trying to get the latest version of Mac OS 9 (9.2.2) working on my beige Power Macintosh G3 (Minitower 266 MHz). However, there's an issue I've been encountering with all versions from 9.1 onward. The OS won't boot. The "Starting Up..." progress bar gets about a tenth of the way full, but then it throws a bomb screen error saying "bus error".

Sean from Action Retro got the same error with his G3 Desktop, and he was able to fix it by reseating the cards. I tried reseating the PCI cards, the I/O card, and the RAM modules, but that didn't fix the issue (although maybe it's because I always smack the side access panel quite hard to get it fully shut).

I can tell that there's some hardware issue with my G3 that prevents it from running later versions of OS 9 (although OS X 10.2.8 works just fine), and I know I'm not the only one who experienced this, since the sticker that was on the computer when I bought it said it ran OS 9.0 and not anything later, although maybe they didn't have any install media for later OS 9 versions.

If anyone knows how to fix this bus error, please let me know.

Do you know what revision of G3 this is? The first ones are notorious for this kind of stuff.

I have a Rev 3 and still have weird problems. Most were resolved using a PCI ATA133 card.

Like bunnspecial said RAM can cause issues like this and they’re extremely picky about it.
They’re equally as picky about the IDE bus which is why I basically bypassed mine.
Is 10.2.8 on the same drive?

 

[LeoI07]

1. Does it happen booting extensions off? (hold shift until the splash screen appears)

2. You said you'd re-seated RAM. What does your RAM make-up look like? These can be funny about RAM sometimes, especially the Rev. A versions. You might try just booting with one stick installed, and if it persists try each of the different sticks you have.

It does happen with extensions off. No puzzle pieces are shown on screen when the error occurs.
My RAM make-up is 3 256 MB modules, with the rightmost one being a darker green than the other two.

Do you know what revision of G3 this is? The first ones are notorious for this kind of stuff.

I have a Rev 3 and still have weird problems. Most were resolved using a PCI ATA133 card.

Like bunnspecial said RAM can cause issues like this and they’re extremely picky about it.
They’re equally as picky about the IDE bus which is why I basically bypassed mine.
Is 10.2.8 on the same drive?

The G3 is revision A (it says that on the inside of the CD drive bezel). As for the IDE bus, I have an IDE to CompactFlash adapter plugged into it, which OS 9 is installed on. 10.2.8 is on the same card, though I don't think that makes a difference since I was still getting the same bus errors before installing OS X.

 

[bunnspecial]

If one RAM module is visibly different, take it out and try.

There again, strip it down to one module if this doesn't work.

Trust me, these first revs can be pickier than you can imagine. When I was working with these a lot, I'd buy 20-30 sticks at a time of LD 256 PC-133 in 10-stick trays, and I'd still have issues in some configs. One of my most bizarre ones was with a Yikes! G4 CPU in an AIO with rev. B LoBo and the only bootable config I found was a single 128mb LD stick...

 

[LeoI07]

If one RAM module is visibly different, take it out and try.

There again, strip it down to one module if this doesn't work.

Trust me, these first revs can be pickier than you can imagine. When I was working with these a lot, I'd buy 20-30 sticks at a time of LD 256 PC-133 in 10-stick trays, and I'd still have issues in some configs. One of my most bizarre ones was with a Yikes! G4 CPU in an AIO with rev. B LoBo and the only bootable config I found was a single 128mb LD stick...

I tried taking out the different module and it didn't fix it. Then I tried taking out another one, and that didn't fix it. So either the bus error isn't being caused by the RAM, or the RAM is merely one of multiple causes of the bus error. I'll leave only one of the sticks in for now.

 

[Project Alice]

I tried taking out the different module and it didn't fix it. Then I tried taking out another one, and that didn't fix it. So either the bus error isn't being caused by the RAM, or the RAM is merely one of multiple causes of the bus error. I'll leave only one of the sticks in for now.

With a Rev A I would assume this is true.
Thus bus error to me sounds like an IDE issue. I’m surprised OS X boots though. Usually it’s the other way around.

 

[LeoI07]

With a Rev A I would assume this is true.
Thus bus error to me sounds like an IDE issue. I’m surprised OS X boots though. Usually it’s the other way around.

Do you know of any fixes for a supposed IDE issue other than bypassing IDE altogether? Do I have to use a different cable or like, mess with the IDE connectors on the logic board?

 

[bunnspecial]

Do you know of any fixes for a supposed IDE issue other than bypassing IDE altogether? Do I have to use a different cable or like, mess with the IDE connectors on the logic board?

Best just to use a bootable IDE or SATA card. The IDE bus on these is an unfortunate mess. I doubt it's a cable issue.

Using a bootable card also gets around the 8gb first partition for OS X and the 128gb drive cap-you can have drives as big as you can find and put OS X anywhere you want on them in any size partition.

Don't forget also that you do have an internal SCSI bus that's fully functional and you can boot off of it(actually internal and external-the SCSI port on the back is the "other end" of the internal bus with an auto-terminating controller in the center). Large 50 pin SCSI drives, or really any 50 pin SCSI for that matter, is getting scarce though.

 

[Project Alice]

Do you know of any fixes for a supposed IDE issue other than bypassing IDE altogether? Do I have to use a different cable or like, mess with the IDE connectors on the logic board?

100% with bunnspecial on this. As I said mine is a Rev 3 and even it has issues with the internal bus.
Mine is set up with 10.4.11 booting off the PCI card, and 9.2.2 booting on the internal bus. This was the only configuration that I could get to work.

 

[philgxxd]

Sorry, didn´t read thoroughly through the posts but one thing came to mind immediately...
Do your OS 9 have the System enabler installed?

 

[Amethyst1]

Large 50 pin SCSI drives, or really any 50 pin SCSI for that matter, is getting scarce though.

Can you use an IDE to SCSI adapter on that bus? That would solve the problem of sourcing drives.

 

[bunnspecial]

Can you use an IDE to SCSI adapter on that bus? That would solve the problem of sourcing drives.

Poking around Ebay a bit, the only one I see that I would trust is $250...

There are a few that claim IDE-SCSI, but the connector on them is a 50 pin SCSI connector and not 40 pin IDE. Those look like your standard 50-68-80 pin converter boards, and I've had mixed luck even with those(I have a huge pile of 80 pin drives and had bought several of those boards to try and use the 80 pins in my beige Macs. I never got anywhere).

 

[Amethyst1]

Poking around Ebay a bit, the only one I see that I would trust is $250...

I was thinking about one of these. Acard seem to know their stuff.

 

[bunnspecial]

I was thinking about one of these. Acard seem to know their stuff.

Yes, I trust Acard. I have several IDE cards from them. They are every bit as reliable as a Newertech card, but the ones I have are in some ways better(I have several 4-bus Acard ones, and I've only encountered one 4-bus Newertech).

With that said, poking around Ebay I saw an Acard bridge listed for $1000, and someone selling what they bill as a remade and improved Acard clone for $250.

I don't see them for sale on that site in a quick look, but given it's an Amiga site I'd not be surprised if it's pricey.

Still, though, it is a viable solution. At that point, though, I'd be hunting for an IDE or SATA card since it will probably be faster than the SCSI bus.

 

[LeoI07]

Alright, the solution I'll be going with is installing Mac OS 9 on a seperate CompactFlash card and booting from that if neccessary. Before I do that, I want to delete the existing OS 9 installation. I think I can use some Open Firmware command to boot from OS X or some external media and delete it from there. However, I don't know what command to use for that, so does anyone know what command to use for booting OS X and also if you can change the default startup OS from the OF prompt? I tried booting off of an OS X CD by holding down C at boot, but I don't see any way to change the startup disk from there.

 

[heath_durbin]

I’m impressed people are using Mac OS 9.???
I have some of those still, but have not turned them on in over 15 years!

actually, I’m going to need to do it in the next month because we’re looking for some old artwork.

 

[Amethyst1]

I tried booting off of an OS X CD by holding down C at boot, but I don't see any way to change the startup disk from there.

But you did get into OS X's installer? If so, you can fire up "Startup Disk" from the "Utilities" menu and change the startup disk.

I’m impressed people are using Mac OS 9.???

It's all but dead

 

[LeoI07]

But you did get into OS X's installer? If so, you can fire up "Startup Disk" from the "Utilities" menu and change the startup disk.

Well that's the thing, the 10.2 installer doesn't have "Startup Disk" in the utilities list.

 

[Amethyst1]

Well that's the thing, the 10.2 installer doesn't have "Startup Disk" in the utilities list.

Oops, my bad. It might be in the Apple menu instead.

 

[LeoI07]

Oops, my bad. It might be in the Apple menu instead.

Nope, everything in the Apple menu is greyed out.

 

[pete1]

Even though this is a very old thread, I can’t help but add my two cents. I am highly positive this issue is caused by a poorly seated Personality card.