Wanted: Info on Optisys/Optidisk WORM file system

jim stephens jwsmail at jwsss.com
Fri Feb 12 14:12:03 CST 2021

On 2/12/2021 11:46 AM, Chuck Guzis via cctalk wrote:
> On 2/11/21 9:31 AM, Chuck Guzis via cctalk wrote:
>> I have a bunch of Panasonic/Matsushita 470/940 MB phase-change WORM
>> discs here--and the appropriate drive (Panasonic LF-5010 SCSI-2) to read
>> them.
> After some digging, I did find that Optisys offered a driver for DOS as
> late as 2008, called Optidriver 2000:
> https://web.archive.org/web/19980624194233/http://www.optisys.com/
> Here's an ad from 1987 that shows an offering:
> https://books.google.com/books?id=x1yigTsvZxsC&lpg=RA1-PA475&ots=5n4IGUBIIU&dq=Optisys%20%22Phoenix%22&pg=RA1-PA475#v=onepage
> Is anyone familiar with this stuff?
> --Chuck

There was a company who made a drive with glass media that a friend of 
ours repped for.

It used a repurposed CD head which was driven hard enough to write their 
media.  it was sold as being able to be written and locked such that it 
couldn't be further modified if need be.  The nuclear security people 
were interested, but ultimately passed due to the size off the player, 
and the need for very long term access to the technology.

The floppies you hear about (off topic) containing security information 
are written with a process that makes it very hard if not impossible to 
alter them w/o destruction of the data at the remote end.

The worm drives had a way to write, then alter by putting in an update 
marker on the media.  You had to work your way to the last version of 
the directory and work your way back to find all the files.  Versioning 
was used to allow updates.  The software package could go back thru the 
data and allow you to see all the updates if need be.

Once you got to full, the media would be marked locked with a special 
area at the inner tracks and from there on would not be updateable.

Mot sure if this is the same operation or not.

They used an regular ESDI interface on the drives they gave us for 
eval.  IIRC basic read and writes could happen on the media, but special 
drivers could be used to make it look more like a flat FAT type file 
from to such as Dos or Windows at the time.

FAT from the standpoint of the software api, file name and the like.  
The structure on the disk was not necessarily physically compatible.

We got an eval unit because I had bought the necessry ESDI controller, 
and we could use the drive.  ESDI was not common at the time and was not 
widely available at that time.  IIRC we had 386 systems AT bus type systems.

I had a sample disk at some point, not sure where it went.  I sent a big 
pile of manuals and specs to Al last year, might have had the stuff from 
whoever we had the drive from in that pile if I still had it.

My partner passed away about 2 weeks ago and would possibly have 
recalled who it was, but can't ask now.  I'll try a scan of our contact 
files and see if "opti" anything shows up.


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