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..
Paul On Fri, Feb 12, 2021 at 2:12 PM jim stephens via cctalk < cctalk@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: > > > > > 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. > > thanks > Jim >