Wanted: Info on Optisys/Optidisk WORM file system
useddec at gmail.com
Sat Feb 13 03:03:19 CST 2021
I think the DEC one was the RX20 or RZ20. It will take a while to find it,
but I'll check the model number..
On Fri, Feb 12, 2021 at 2:12 PM jim stephens via cctalk <
cctalk at classiccmp.org> wrote:
> 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:
> > 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
> 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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