History (1991): IBM Gives Up 12-Inch Optical Discs for 5.25-Inch Media

Even for its largest ImagePlus configurations under MVS/ESA, IBM Corp. (Gaithersburg, MD) is taking out of its catalog LMSI’s 12-inch optical disks and their jukeboxes originated from FileNet, to replace them by systems using smaller 5.25-inch media.

But these new products won’t be officially available before June 92.

Until now, Big Blue never really had pushed its ImagePlus’ (a general term that includes all its offers in electronic management) customers into opting for optical discs, it rather preferred selling its own magnetic disk units, faster but much more expensive.

Probably forced by its customers, IBM had however one optical offer, 9246s and 9247s based on 12-inch media.

Why is IBM now choosing discs, always WORM type ones, in a smaller format?
Little disks turn faster, which means faster access times, transfer rates and loading/unloading times per disc in smaller jukeboxes, there are many suppliers for this type of media, which means prices lowering, explains Mark Morin, VP Image Solution, IBM Corp.

The late availability of these new products is going to force ImagePlus customers who are interested in optical storage to be quite patient, and, meanwhile to be contented in large magnetic disks.

Guess who’s going to take advantage of it?
The 5.25-inch announcement concerns 3 jukeboxes named 3995 Optical Library Dataservers. Big Blue has not yet unveiled the origin of the products.

For sure, the automatic libraries come form Hewlett-Packard. According to a Gartner Group’s consultant, the drives would be made by Mitsubishi, but Mike Randall, in charge of storage products at Mitsubishi Electronics America, could not confirm it.

IBM would change from Matsushita to Mitsubishi for 5.25-inch WORMs (Big Blue had offered, with no big success, a unit bought from Matsushita/Panasonic for its microcomputers).

This time, each optical disc in a cartridge has a 610MB capacity on both sides and a unit price of $180 for a minimum order of 10 units. The 042 jukebox, for ASI 400s holds 32 media. For MVSI ESA environment, a basic model 132 can support 144 discs but an extra 112 unit with 144 more discs can be added: this brings the total capacity to 176GB.

DFSMS can support up to 28 of these subsystems, this offers a volume close to 5TB that can be accessed by one single processor. IBM explains it has made changes to optical products as a parity checking of data and mainly by adding on each jukebox a cache memory on magnetic disk much faster with a capacity of 160 or 300MB. This magnetic cache technology, that the French company Dorotech had pioneered, but under Unix, can improve performances of the subsystem.

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue 40, published on May 1991.