The best data storage system that never took off.
 

So who here remembers PD/CD ?
I belive it first appeared in the early 90s ..pre win95
but was adopted by businesses rather than home use as it the drives were expensive ..as was the media.
It came in 2 flavours..
first SCSI interface and later IDE.
The units were capable of reading PD discs and CD discs.
PD was what grabbed my attention.
Phase change Dual
The media/discs were in cartridge form so as to limit exposure and avoid touching or damaging the pre sectored discs.
Most discs had a storage capacity of 650mb ..which was huge in its day.
Single Sided but rewriteable.
The basic principles were based on Magneto Optical and used a combination of Magnetic flux changes and laser light to write the data.
I have only one SCSI unit sadly ..but 3 IDE units.
So ..what made them special.
Well my early scsi unit was used to write data to many discs back in the days of win 95 ..and having recently checked the stored data (over 20 years later) ..there is NO data loss.
..and I suspect the data will last longer than I will.
A true 'set in stone' medium imo
Hard drives fail mechanically ..floppies and tape suffer bit rot and surface corrosion....modern discs that use dyes to store data are unreadable after 10 years...Yet the PD data retention appears to be indestructable ..barring physical damage.
The fore runner of the modern CD/DVD ...but expensive and made to last.
rgds
VS

Re: The best data storage system that never took off.
 

They weren't particularly useful though because for backup at the time, DLT was much much much better and we used Zip disks for everything else.

Re: The best data storage system that never took off.
 

Agreed Mr B ..
But the reason I love 'em is the durability of that stored data.
I honestly dont think anything comes close though there was a modern disc media storage medium which made similar claims..though I never tried it.
Literally written in stone ..M disc .
Again ..never took off.
rgds
VS

Re: The best data storage system that never took off.
 

DVD-RAM was marginally popular for a bit in the 2000s if I remember. That was sort of a successor.

However one event rather put me off it in 2004. A software guy I was working with carried his life's work around on one. Promptly whacked it in a ridiculously fast Pioneer slot loader drive. It got faster, and faster, and faster, then BANG the disc exploded into pieces, most of which got shot across the room from the drive. That was his only copy.

Alas the "multiple backups" lesson was taught to a lot of people that day but I'd have hated for it to be me.

Re: The best data storage system that never took off.
 

I think the company where I had my first full time job used PD discs for storing scanned documents, certainly it was medium like it that looked like a CD in a caddy.

I remember I had to walk across the room to a bank of drives to find a disc with a particular file on, if it wasn't already in a drive.

One of my ex-girlfriends had a VHS / DVD recorder that came with a blank DVD-ROM disc in a caddy for recording on.

Re: The best data storage system that never took off.
 

Doesn't the recordable version of MD (minidisc) use the same magneto optical principal, or at least a similar one?

Re: The best data storage system that never took off.
 

You could be right Duncan ..though I can't confirm it ..having never opened one.
rgds

Re: The best data storage system that never took off.
 

It sounds familiar, certainly it polarises the bits on the disc.

There was a short lived MD-RAM format for computers IIRC, I remember seeing in a Hi-Fi magazine.

Re: The best data storage system that never took off.
 

MO discs and drives up to 2.3GB? I have some sitting in a cupboard somewhere that I used earlier.

Re: The best data storage system that never took off.
 

When I was an young engineer at southern rentals our head office in Hove had a new computer system installed. The new IBM had 4 or 5 Winchester stacked disc units for data storage. each of These disc stacks were about 14 - 15 inches in diameter and about 10 disc high. This was about 1973/4. The computer system took up 3 rooms.

Bob.

Re: The best data storage system that never took off.
 

I used one occasionally to back up photo scans....my wife's desktop PC had a PD drive in the late 90s. I never saw another before or since. I guess CD-ROM drives very soon became affordable...then DVD drives and flash drives.

Re: The best data storage system that never took off.
 

If read-only CD-ROM drives had not become as ubiquitous as they did, popularised by the emergence of IDE CD-ROM drives bundled with sound cards having a matching interface on board, then Magneto-Optical drives might have stood a chance in the market. But then the first recordable CD drives came out, and the game changed suddenly. The "read anywhere"-ness of CDs won out over the higher capacity of the MO discs, and the advent of IDE CD recorders -- obviating the need for an expensive SCSI card -- was the final nail in the coffin, especially once motherboards began sporting sound chips and a secondary IDE interface.

Re: The best data storage system that never took off.
 

Danmere Backer
For the first time I had a backup medium measured in gigabytes!

Imagine that, 4GB of data on an ordinary VHS tape. Mind-blowing.

Re: The best data storage system that never took off.
 

I have a 5 1/2" scsi pd drive and a number of disc's if any one want to come and collect them. the drive is very heavy. some disks are double sided so you turn them over to get the extra space.

items are in frinton on sea.

Re: The best data storage system that never took off.
 

I don't remember that format, but the community radio station I helped found and had a show on until 10 years ago had a 360 Systems Digicart/II system for a while - used Iomega Bernoulli 5.25" 105 MB disks.

Re: The best data storage system that never took off.
 

I used to have a PD-ROM drive plus discs when I was running Windows 95 (and then later, Windows 98?). I found that they were an excellent medium for storing backups. Prior to that, I used mag. tape cartridges.

Al.

Re: The best data storage system that never took off.
 

I suppose you could add Sega's GD ROM Storage system to the list.
Was developed for the dreamcast and arcade machines as an alternative to the expensive then DVD System.

Re: The best data storage system that never took off.
 

One "read only" data storage system that never took of was not really electronic at all. 35mm film, not used to project moving images as in a cinema, but with each frame consisting of a separate picture. Either a page of text or an illustration.
The images being back projected on to a small translucent screen.

The fire brigades used this to carry on the fire engine, details of industrial chemicals and on how to proceed in case of fire or other accident involving these.
An alphabetical or other index was shewn on the bottom of the screen.

So if a fire officer found that CYCLO-HEXANE was involved in fire, they would "fast forward" the film until the index letter reached C and then slow forward until the desired entry was reached. This might consist of a dozen frames giving details of the properties and risks of the material.

A similar system was proposed for hospital casualty departments, giving details of relatively rare accidents, diseases, and poisons, Things that the average doctor might see but once, or never in a working lifetime.

Re: The best data storage system that never took off.
 

It sounds similar to microfilm.

McDonnell Douglas developed a transparent video disc format with the data encoded as lots of black dots printed on.

It only had a short playing time for video, but they put it to good use as a way to store technical information for their aircraft.

Re: The best data storage system that never took off.
 

Yes, very similar to microfilm but a single roll of 35mm film was said to be simpler and more robust to store, transport and use.
I used to have one of the readers, but gave it away to someone interested in vintage fire fighting equipment.
Purchased cheaply from a shop in the Tottenham court road.