Fitting a Magneto Optical drive into a Power Macintosh G4

Kai Robinson

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While you may know that Power Macintosh G3 & G4 machines came with ZIP drives installed (as a CTO option), you can use any other ATAPI 3.5" device in that bay - it doesn't have to be a ZIP drive. In this instance, i'm going to install a Fujitsu MCE3130AP 1.3GB ATAPI Magneto Optical drive in it.

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"But what about the bezel" I hear you say! No need to worry - the bezel, and the eject hole line up just right!

First things first, open up your mac, remove the front drive bezel surround carefully, unscrew the cage from the front, and disconnect the IDE & Molex power cables.

Now some manufacturers drive will have no issue with mounting in the case, however, the Fujitsu drives seem to mount 'upside down - ie, the controller board is on top, with the molex plug inverted. If this is the case, you'll need to modify the rear of the cage.

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I removed this with nothing but pliers, it's held in to the main part of the cage by a kind of rivet process, but it's just enough to hold it in place. You should end up with something like this:

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Now just slot the drive in, and secure it with standard drive mounting screws.

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It might look as through this stands proud, but actually this is normal, and actually benefits from being slightly further forward, to match the bezel better.

Once you have the drive in place, slot the cage back in and screw it back into place.

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Put the bezels back in place and....oh would you look at that!

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Fits just about right, and the eject hole even lines up enough to be able to press it, with a paperclip, if you need to eject manually.

What about the OS though? Do you need drivers?

Nope! They just work™️!

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Disks just show up just like any other piece of removeable media. Beautifully plain and simple.

I wish Apple had gone with standard MO instead of the cheaper, more ubiquitous (and unreliable) ZIP.

Unlike ZIP, the sizes scaled - you can get them in upto 2.3GB capacity disks. Drives can be expensive, but they're definitely worth it. They're silent, resilient and a great way of transferring files between macs.

I have another two 3.5" Fujitsu drives, also 1.3GB, but SCSI, for mounting both inside a mac (probably my 9600 in place of it's ZIP drive), and externally, in a SCSI enclosure.

Remember though, that the drive needs to support the disk being used. I.e. a 1.3GB drive can accept all disk sizes upto and including 1.3GB, but an old 128MB or 230MB drive can ONLY accept media upto the limit of the drive.
 
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Mr. Fahrenheit

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Sep 2, 2021
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I see you took a page from my book! All the better. We should all change out our Zip drives for MO drives in our Mac’s. Or even the floppy drive in some like the Lc475 with an MO drive in it’s place. I mean, who uses physical floppy disks anymore? 😜

Now you just need a set of these.
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Kai Robinson

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I see you took a page from my book! All the better. We should all change out our Zip drives for MO drives in our Mac’s. Or even the floppy drive in some like the Lc475 with an MO drive in it’s place. I mean, who uses physical floppy disks anymore? 😜

Now you just need a set of these.
View attachment 3074View attachment 3075View attachment 3076View attachment 3077

Yes, i damn well need those - trying to get the firmware flashed on my G4 with Leopard is a pain - without repartitioning and reformatting everything...!
 

Paolo B

Tinkerer
Nov 27, 2021
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Nagoya, Japan
Hi All,

Should any of you be interested, I finally managed to get a decently neat installation of a MO drive in place of the internal floppy in a SE/30.
Not a super easy one, but doable.

Out of the few units I have around, I opted for a Fujitsu M2513A 640Mb SCSI:
1) it’s from 1997, not exactly “period correct”, still fully compatible with early 90’s hardware
2) it’s nicely built, with all metal bits.
3) moreover, has the key characteristic of loading the disk horizontally (disk is not “seated”, just loaded in) which is a key feature, as the height of the cartridge allows no tolerance for any misalignment or vertical movement with respect to the front bezel floppy slit.
4) eject is motorized, but loading is manual and this unit can be mounted sufficiently flush for pushing the disk manually until it gets loaded, without modding the chassis of the drive.

So, surely, I wanted to have something with absolute minimum mods on the drive side and zero on the Mac side (except for the floppy drive cage, for which I have a couple of spares).

What had to be done

- Custom “short neck” 90 deg right angle molex connector.
- Custom mounting brackets for height alignment between the drive and the floppy slit on the bezel.
- Custom SCSI cable, fitting into the extremely tight packaging space (you also want to keep the regular HD…)
- Floppy drive mounting cage had to be modified, creating new openings for allowing right alignment and sufficient clearance for molex and SCSI cable.
- Eject button had to be desoldered, a new one wired in and mounted on custom built bracket for correct alignment with the front bezel pin hole

Remarks

Disk formatting: the Fujitsu utility gives very little control, with HDT you can create bootable disks.
However, System 7.1.1 > boots fine, System 7.5.3 > hangs after “welcome to Mac” splash screen, other OS > not tested yet.
Most annoying: the unit gets unpleasantly noisy. I guess it’s because it’s all packaged so tightly, that there’s no longer an effective decoupling against structure borne noise.

To be done:
1) Optimize length and layout of the SCSI cabling.
2) Add an activity led.
3) Find a reasonable fix for the noise.
4) Test different versions of the Mac OS.
5) Maybe, design a new bracket for a 3D printed solution, or - even better - metal plate cutting and bending.

If someone is interested, I can take more pictures and share more details, as I’m planning to keep on working for improving the solution.

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Kai Robinson

TinkerDifferent Board President 2023
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Hosting the file linked to, as clicking the URL doesn't work.
 

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retr01

Senior Tinkerer
Jun 6, 2022
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I have some questions:
  • How many times rewrites on a MO disk before it's no good? Forever?
  • Better storage life than floppies?
  • Faster than CDRW? Just as fast as an HDD?
 

Paolo B

Tinkerer
Nov 27, 2021
258
144
43
Nagoya, Japan
I have some questions:
  • How many times rewrites on a MO disk before it's no good? Forever?
  • Better storage life than floppies?
  • Faster than CDRW? Just as fast as an HDD?
# forever
# up to 1000 times better (1.3 Gb)
# yes / almost (depending on what you benchmark)

Don’t know why the standard did not become the “new floppy”, it ticked all the boxes. In Japan it was hugely popular, elsewhere more like a niche, fancy storage media.