• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Using Magneto Optical drives on vintage 68k Macs

MrFahrenheit

Well-known member
I’m starting to see a repetitive issue that I might have narrowed down to the MDF magneto optical extension 2.3.8.

I get random Finder crashes when copying from a MO disk on Mac OS 7.6.1 on my recapped and overclocked Mac LC 475 with a full 68040 CPU. The CPU is certified for 40mhz and it’s a real one.

I have changed out physical MO drives, replaced SCSI cables and terminators. Booted clean installs. And still, when coping I get a random freeze. Sometimes I can get only 10MB into a file copy before it freezes and sometimes I can get a couple of disk swaps of copies before I get another freeze.

Has anyone else seen a freeze copying files in the finder with this extension enabled? I’ve experienced the problem even when copying from a different drive, with that extension enabled, but no compatible MO drive connected on the system.

I just realized that extension might be the cause of the issues I’m having so I’m going to spend the morning troubleshooting without it installed.

I also saw this issue last year with my G3 beige board copying from MO disks under Mac OS 8.1 and I thought it was something else. Same M.O. (pun intended).
 

zefrenchtoon

Well-known member
I’ve found a Verbatim driver that was on a Mac formatted disk back in the days. I don’t remember if I uploaded it or not on the Garden. Do you want to test it ?
Else I used Drivor to manage my MO drives … I have to upload it on the garden.

Edit: here is the first one:
 

olePigeon

Well-known member
@zefrenchtoon Ooo, thanks for the new driver. Didn't know they had one.

@MrFahrenheit One of my MO drives that I transplanted into an external case would cause my computer to crash. Turned out to be SCSI termination. Something about the case just didn't work, even with a terminator and set to the last ID.
 

MrFahrenheit

Well-known member
@zefrenchtoon Ooo, thanks for the new driver. Didn't know they had one.

@MrFahrenheit One of my MO drives that I transplanted into an external case would cause my computer to crash. Turned out to be SCSI termination. Something about the case just didn't work, even with a terminator and set to the last ID.

I've solved the problem, with a few steps taken. The final step that resolved the issue was changing out the Mac logic board. Something glitchy with the board I was using, which this was happening on.
 

olePigeon

Well-known member
@zefrenchtoon @MrFahrenheit That Verbatim driver lead me to discover MacPEAK who wrote lots of different drivers. They have SpotOn and SuperSpot, which I can't really tell the difference. Then there's the Verbatim one that was written by MacPEAK and called "Cache Utility," but doesn't match either SpotOn or SuperSpot.

According to MacWorld March 1994 issue, SpotOn and SuperSpot are two different products. SuperSpot is listed at $150 with SpotOn $100, so I would assume that SuperSpot is either a more feature-rich product, or, a newer version of SpotOn. However, the versions uploaded to Macintosh Garden would lead me to believe otherwise given their copyright dates. *shrug*
 
Last edited:

MrFahrenheit

Well-known member
I’ve found a Verbatim driver that was on a Mac formatted disk back in the days. I don’t remember if I uploaded it or not on the Garden. Do you want to test it ?
Else I used Drivor to manage my MO drives … I have to upload it on the garden.

Edit: here is the first one:

Thank you @zefrenchtoon for finding and uploading that driver! Really appreciated!!
 

olePigeon

Well-known member
Neither SuperSpot nor SpotOn would mount my 2GB MO disk. Nor does the Verbatim. However, I did not erase the disk using their software. It may be that they require the disk to have the MacPEAK disk driver installed before the extension can work with it.

Incidentally, I may have run into a memory issue with the Fujitsu driver. So I'm going to try the Pinnacle driver for a while.

Edit: Tried a 230MB disk and it worked fine. So those particular drivers may not work with higher capacity disks, or, has the software version of the pre-3.2.6 JackHammer bug where it won't work with disks with sector sizes larger than 512b.
 
Last edited:

zefrenchtoon

Well-known member
Thank you @zefrenchtoon for finding and uploading that driver! Really appreciated!!
You're welcome!

My father used MO drives to backup its data between 1995 and 2000-ish.
We had a 230 then a 640 drive but we used mainly 230 disks and some of them were sold as "Mac Format".
I've found this driver on one of my old SCSI HDD.
Also, we had different software with our drives ("Drivor" was one of them). I have to find enough time to backup all of them on the Garden.

About Drivor, I did a post on the Garden's forum:

Here are some screenshots of it:

About our 640 drive, it was unstable. :(
Now, it seems to want to "eject" even if there is no disk in it. (DynaMO 640SE if any of you have an idea)
 

olePigeon

Well-known member
@zefrenchtoon Wow, thanks! I don't know why I'm obsessed with the drivers as much as the media and drives themselves. :D I just love MO tech. It's so cool. I think because it's similar tech to all the other cartridge systems, but nearly identical size as a floppy disk for the 3.5" version. The 5.25" versions just look like oversized 3.5" floppy disks. Very aesthetically pleasing. :)
 

olePigeon

Well-known member
Just an update: So far no memory leak issues with the Pinnacle driver. I was running out of System memory (Finder?) when using the Fujitsu driver, making it impossible to do something as simple as Get Info or copy a file. But I'll need to do some more comprehensive tests. It could also have been an extension conflict of some sort causing the memory issues.
 

olePigeon

Well-known member
About our 640 drive, it was unstable. :(
Now, it seems to want to "eject" even if there is no disk in it. (DynaMO 640SE if any of you have an idea)

I wonder if it has a button similar to a floppy drive to tell it when it has a disk inserted. If that's the case, then it may just need some contact cleaner sprayed into it, press the button a bunch, and give it another go. If the button is stuck (which can happen in a regular floppy) it'll constantly attempt to eject because it thinks there's a disk, can't read it, then ejects.
 

MrFahrenheit

Well-known member
Just to update this thread, I've found the best solution for MO disks and drives is this formatting tool:


It includes an extension that can mount MO disks, and when the disks are formatted with that tool, they are fully bootable. It works with 3.5" and 5.25" MO disks, of capacities all the way up to 9.1GB, and fully supports System 7 through Mac OS X.
 

zefrenchtoon

Well-known member
Just to update this thread, I've found the best solution for MO disks and drives is this formatting tool:


It includes an extension that can mount MO disks, and when the disks are formatted with that tool, they are fully bootable. It works with 3.5" and 5.25" MO disks, of capacities all the way up to 9.1GB, and fully supports System 7 through Mac OS X.
It was me who shared the old version on this page 😅
I recall to have used it too to manage my father's MO drives.
It was along with the Verbatim one on my HDD.
 

zefrenchtoon

Well-known member
@zefrenchtoon Wow, thanks! I don't know why I'm obsessed with the drivers as much as the media and drives themselves. :D I just love MO tech. It's so cool. I think because it's similar tech to all the other cartridge systems, but nearly identical size as a floppy disk for the 3.5" version. The 5.25" versions just look like oversized 3.5" floppy disks. Very aesthetically pleasing. :)
I love it too and I am like you about drivers :D
That's why I saved the Verbatim one long time ago.
 

olePigeon

Well-known member
@zefrenchtoon That one is IDE, not SCSI.

Same seller has 2.3GB SCSi version for $120, which is the highest capacity drive.


And here's the SCSI version of the drive you were just looking at for $90, just $10 more:

 

olePigeon

Well-known member
And the 640MB drive for just $70:


Honestly, the 640MB media is the best value. It's a very common capacity and usually fairly cheap relative to the 1.3GB and 2.3GB media.
 

olePigeon

Well-known member
Also, all those drives are backwards compatible with smaller capacity media. So if you go with the 2.3GB drive, you can still buy and use the cheaper 640MB media. Every now and then someone lists 1.3GB and 2.3GB media without price gouging. I've managed to collect 5 2.3GB disks over the years for about $10 a disk. It's rare, but not impossible
 
Top