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Software for writing to MO WORM discs?

Mr Fahrenheit

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Okay, I know I sound like an idiot, but I think the info I posted Sept 21 about CCW discs not being compatible is wrong, and that my first bit of information is actually correct.

An excerpt from further in the same manual is where I saw CCW. See here:

C467C7B3-226C-447D-8F8D-667C048328A5.jpeg

This is found in the appendix. The first part of the manual, with a chart, doesn’t say CCW but just the CWO-xxxx, which is where I thought I was going wrong yesterday.

You’ll see specifically the mention of CCW here, or “continuous composite write once”. Whoever can figure out these abbreviations and acronyms could deserve a medal. How EDM means rewritable is beyond me.

So, having purchased a batch of CCW 2.6GB 1024 byte per sector WORM media, which the manual lists as compatible, I’m certain the problems I saw trying out a disc in my two drives is down to the right software.

So, back to the original question asked pages ago here, what in the world is the correct software for formatting and writing these darned things?

I have tried every tool available on Macintosh Garden and all report some form of error when trying to initialize a cartridge.

Unless…. I somehow buggered up my first attempt and it ruined the first disc. Maybe I’ll try some other software tools in a different order on some fresh discs.

In the meantime, I’ve bought a handful of 5.2GB WORM disks to see if they make any difference. We’ll see when they arrive.
 

olePigeon

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It would appear that Sony uses the term "CCW" in different ways. CCW in that they're all Continuous Composite Write-Once disks. But "CCW" must also mean something else to Sony. They even have "CWW," whatever that is. I guess for Sony, they mean their -B suffix disks. Some examples:

CWO-1300B
CWO-1300C CCW
CWO-5200C CWW

I don't know what the heck the difference is. But I think that with WORM media not being compatible between different vendors would be a pain in the butt. Which is a shame because the media is comparatively cheap.

Hopefully there's some commonality between the Sony -B disks and the media produced by IBM, HP, and Plasmon (which all seem to be the most common.) IBM's technical website makes zero distinctions between its different WORM media. It just states to assume they're all "CCW" for SD, DD, 2x, 4x, 8x, etc., but I don't know in what context they're using "CCW."

Edit: I'm wondering if "CCW" and "CWW" are media that are written to more like a tape drive. The raw data is auto-compressed and accessed via an intermediary that recovers it. That's in contrast to using it more like a write-once HDD.
 
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Chuck(G)

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I was under the impression that the various types referred to technology; i.e. ablation vs. phase-change, etc. Maybe not, perhaps. Some MO drives appear to handle several types.
 

Mr Fahrenheit

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What’s really strange is, I managed to write a SCSI disk driver to one of the CCW WORM discs, but when it comes to formatting a usable partition it gives an error and fails.


Here’s a picture of a WORK disc with the driver installed and a corrupted partition.


8CC0F0AA-8094-45E9-8BDA-8D0C12CB42A1.jpeg
 

krebizfan

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I found a Sony brochure from 1996 which has CCW as the direction of rotation. Apparently, there were other drives that rotated clockwise. EDM is used for rewritable discs while CWO is used for write-only discs. If the estimate of more than a billion read cycles is accurate, the disc should be able to be read continuously for centuries.
 

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bear

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Do you suppose that formatting attempts to update/write more than once to the same sector?
That's exactly what I think.

"MO" doesn't automatically imply "WORM". If the tools aren't specifically for WORM disks, you're going to create an expensive piece of garbage every time. You can't treat WORM disks as if they are "normal".
 
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Mr Fahrenheit

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That's exactly what I think.

"MO" doesn't automatically imply "WORM". If the tools aren't specifically for WORM disks, you're going to create an expensive piece of garbage every time. You can't treat WORM disks as if they are "normal".
Right. Which is the reason for this thread: finding the software that is used for making WORM discs work on Macintosh.

I’ve downloaded and tried every tool I can find. I could list them here for completeness.
 

Mr Fahrenheit

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Do you suppose that formatting attempts to update/write more than once to the same sector? That's a no-no on WORM.
My guess is about the same as yours. I was thinking it writes the SCSI driver and a provisional partition to the disc successfully. Then attempts to convert the provisional partition into a working one, but the disc sector storing the partition map was already written once, so it puts an error up because it couldn’t write an updated partition map to the disc.

My guess is the process is “correct” for a SCSI disk, but not for a WORM disc. The tool thinks it’s a regular SCSI disk that’s experiencing write errors and aborts the rest.

What we need is a tool that prepares the SCSI disc driver and partition map and partitions all at once, without being a multi step process.

I’ve tried tools from FWB, La Cie, APS, Pinnacle Micro, and Software Architect’s (which ships with these drives).
 

Chuck(G)

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Other than using an WORM disc filesystem driver, I believe that your only practical option to get a normal HFS+ readable disc is to prepare an image of the disc and then write the whole thing at once. Of course, you don't want to bother with writing the unused sectors, but you get the idea. This would be simple enough to do using Linux and the loop device, but I confess not knowing enough about the internals of old Mac OS to venture a guess at a method.
 

Mr Fahrenheit

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Other than using an WORM disc filesystem driver, I believe that your only practical option to get a normal HFS+ readable disc is to prepare an image of the disc and then write the whole thing at once. Of course, you don't want to bother with writing the unused sectors, but you get the idea. This would be simple enough to do using Linux and the loop device, but I confess not knowing enough about the internals of old Mac OS to venture a guess at a method.

I might make a partition on a 9.1GB MO RW disk that equals the space of the 2.6GB MO WORM disks that I have, and copy files over to it.

Then, hook up the MO drive to my Power Macintosh G5 running Mac OS X 10.4.11, and do a dd of the ~1.2GB partition from the RW disk, to a file, and then do a dd of that file back to a WORM disk and see if it works. That would write the entire thing out at once, and it would image the required SCSI disk driver over. I don't know when I'll have time to test this, but it seems to be the best test of a theory.
 
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NeXT

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I know we are limited here by your hardware availability but why not just go with magneto optical at this point and flip the write protect switch? There is an insane amount of workarounds at play here.
 

Mr Fahrenheit

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I know we are limited here by your hardware availability but why not just go with magneto optical at this point and flip the write protect switch? There is an insane amount of workarounds at play here.
Because the idea of using a WORM disk intrigues me, and I want to learn how this works, exactly. It’s the reason I use vintage hardware, to experience it.

I don’t want to take the easy way out. I want to know what is needed and what it’s like to write files to a WORM disk.
 

Unknown_K

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Weird obsolete and forgotten media is fun to play with which is why I have a two internal and one external WORM 3363 drives for my IBM PS/2 line (actually the external has an ISA controller I think).
 

Chuck(G)

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I think you copied some stuff for me on one of those weird PS/2 WORM drives. I recall looking at the details of the interface and feeling mild nausea.
 

Mr Fahrenheit

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I found a review of Magneto Optical drives in Macworld Magazine, August 1997, page 116.

Here is a shot of the various drives, and it lists the software each included. Documenting here because a lot of these details are lost to time.

macworld-aug-97-pg116.png
 

Chuck(G)

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That's not all that helpful, is it? None of the drives listed under "Optical Drives" is a WORM unit--they're all rewritable as far as I can tell. I still have a disk for the Pinnacle Apex.
 

Mr Fahrenheit

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That's not all that helpful, is it? None of the drives listed under "Optical Drives" is a WORM unit--they're all rewritable as far as I can tell. I still have a disk for the Pinnacle Apex.
Right, but the 5.25 MO drives claim to support writing to WORM media. So wouldn’t that make them multifunction RW/WORM units ?
 
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