Classic Computer Magazine Archive COMPUTE! ISSUE 70 / MARCH 1986 / PAGE 18


Selby Bateman, Features Editor

Dramatic changes are occurring in the ways we store computer information. Technological advances and lower production costs are affecting both magnetic and optical data storage media. Traditional 5¼-inch floppy disks are giving way to 3½-inch microfloppies. Hard disk drives are rapidly becoming cost effective for average users. And low-power lasers are making optical storage technology the medium of the future. Here's a look at how far and how fast data storage technology has come, and where it's headed next.

Just when we think we're getting used to the pace of change, technology surprises us again. Consider the following important changes to the ways we store computer data:

  • Apple Computer introduces its UniDisk 3.5, a 3½-inch disk drive for the Apple IIe and the Apple IIc computers that can store up to 800K (kilobytes) of information, more than five times the amount of the standard Apple 5¼-inch drives.
  • New 3½-inch drives are included as standard storage systems for Atari's 520ST and Commodore's Amiga, joining Apple's Macintosh which was introduced with the drive in 1984. Industry sources believe IBM will also begin using the faster, more powerful 3½-inch drives sometime in 1986.
  • Blue Chip Electronics says it plans to offer a 3½-inch disk drive for the Commodore 64, tentatively priced at about $100. Commodore insiders admit that they already have the technology to offer a 3½-inch drive and a 10-megabyte hard disk drive for the 64 and 128 (although no plans to market these peripherals have yet been announced). Atari also has been considering a 3½-inch disk drive for its line of eight-bit computers.
  • Haba Systems is marketing a low-priced ($699) 10-megabyte (10,240-kilobyte) hard disk drive for the Atari ST. Prices for 10- and 20-megabyte hard disks fall as low as $400 for some computers. Hard disks on a card are announced for the IBM PC.
  • Toshiba, Hitachi, Philips, and several other companies announce CD-ROM (Compact Disc-Read Only Memory) players that can store entire encyclopedias or massive software libraries on just a portion of a 4¾-inch optical laser disc.
  • Maxell Corporation shows a new 2½-inch microfloppy disk drive that it plans to sell to manufacturers for use in laptop computers. The company also announces a 5¼-inch eraseable, reusable optical laser disc, which is to be marketed by 1987, and a new high-density perpendicular magnetic recording disk that packs up to 100K of data per inch.
  • Sony announces a writeable optical laser disc storage system for computer use in business, science, and major archival applications capable of storing up to 3.2 gigabytes (3,276 megabytes, or 3,354,624 bytes) per disc.

Virtually every week, another advance in data storage technology surfaces within the computer industry. What's going to happen to all of the 5¼-inch floppy disks we're using now? Listen to Maxell's Ted Ozawa, vice president of the computer products division: "While we expect floppy disks to continue as a major industry factor for at least the next ten years, new technologies offering more portability or more storage capacity are being developed more quickly than previously anticipated."

Apple Computer's UniDisk 3.5 is a double-sided floppy disk drive that stores 800K of data, one of a growing number of 3½-inch drives for popular microcomputers.

Ozawa's comments are being echoed throughout the computer industry as breakthroughs in storage technology are coupled with swiftly falling prices. Even casual computer users are beginning to think in terms of megabytes—and, with CD-ROMs, gigabytes.

The computer industry is rapidly advancing in two related areas of technology. The most immediate and visible changes are the advances in magnetic technology, ushering in low-cost, high-capacity disks and drives for the mass market. At the same time, a second technology is gaining speed, less visible but more important in the long run: laser discs designed for audio and video players are being tailored to computer data storage.

To understand the economies of scale involved with recent data storage improvements, consider that a typical 5¼-inch double-density IBM floppy disk holds approximately 360K of information. (By comparison, a Commodore 64 disk holds about 170K.) A double-sided 3½-inch disk contains approximately 800–880K of data. And an optical laser disc typically holds 550 megabytes, or the equivalent of almost 1,500 floppy disks (more than 3,500 Commodore 64 disks; more than 4,000 Apple II disks).

Such capacities are a far cry from the data storage devices used by many of the early microcomputer owners. A few years ago, modified audio cassette recorders were common storage devices on personal computers. They were inexpensive and usually reliable. Purchasers of Commodore VIC-20s, for example, and later Commodore 64 buyers, generally used Commodore Datassette recorders as a way to get started in computing for a fraction of the cost of a disk drive.

As with so much in the microcomputer field, magnetic tape storage was a descendant from mainframe computer systems. A cassette tape is a sequential access device. That is, tape moves sequentially across a recording head. In order to get to a program at the end of the tape, all of the preceding tape has to pass by the head first. The result is a frustratingly slow access time. More recent magnetic tape storage devices have used improved technology—data compaction, shorter loop tapes, and faster speeds—to remain competitive, at least as backup systems for hard disk drives.

With the advent of circular magnetic disks, also descendants of mainframe systems, many computer users decided to switch to the new medium. Although more expensive, random access storage offered significantly greater speed. A moveable read/write head could find information anywhere on the spinning disk almost instantaneously. The first floppy disks were either 8 inches (from IBM) or 5¼-inches (from Shugart) in diameter. But the emerging micro industry quickly agreed on the smaller 5¼-inch disks that predominate today.

During the past three years, an even smaller-sized magnetic disk, the 3½-inch format, has gained popularity. With its faster access speeds, 800K double-sided, double-density format, and sturdy plastic shell, the 3½-inch disk has definite advantages over the 5¼-inch standard. But when first introduced, so-called microfloppies came in at least three different sizes. Sony sold the 3½-inch disk, Dysan offered its 3¼-inch style, and Hitachi announced a 3-inch model. How did the 3½-inch disk become today's de facto standard?

"The thing that happened was that Sony was very aggressive in promoting its format, not only to media [disk] makers but to drive makers," says David Berry, product manager for Maxell, a division of Hitachi. First Hewlett Packard and then Apple Computer adopted Sony's 3½-inch format, which created a snowball effect toward the Sony size. Hitachi still markets its 3-inch model, primarily in Japan and Europe, notes Berry. In fact, Maxell just introduced an even smaller, 2½-inch disk, that it hopes to sell in selected market niches. "But," admits Berry, "we definitely think the 3½-inch will be the dominant force."

Maxell's new ultra-micro 2½-inch floppy disk holds 500K of unformatted data and is planned for use in laptop computers and other selected markets.

Regardless of their size, the physics of one floppy disk is similar to that of any other. An outer sleeve (vinyl for 5¼-inch; hard plastic for 3½-inch) protects a circular disk that rotates on a disk drive's spinning hub at hundreds of revolutions per minute. There is a ferrous-oxide coating on one or both sides of the disk. The drive's read/write head (or heads, if the drive is double-sided) can read and alter the arrangement of magnetic particles Information is recorded on the disk in concentric rings, or tracks, that are divided into arc-shaped sectors. Drive and disk manufacturers are continually improving this technology to allow increasing amounts of data to be accessed at faster speeds. The newest floppy disks are capable of megabytes of storage, such as the IBM AT's 1.2-megabyte floppy or Maxell's recently developed 10-megabyte metal-formula floppy disk, which contains 41.7K storage space per track and 120 tracks per side.

Looking similar to a standard 31/2-inch microfloppy, Maxell's new perpendicular recording disk stands magnetic particles on end to pack up to 100K of data per inch, about ten times the amount of a normal microfloppy.

The next quantum leap in magnetic computer storage media is coming soon in the form of perpendicular recording technology. Magnetic floppy disks have heretofore used a standard metal oxide coating in which the particles lie horizontally on the disk surface. Perpendicular, or vertical, recording is analogous to the principle that more people can occupy a given space standing shoulder-to-shoulder than lying down side-by-side, explains Maxell's Ozawa.

Picture the magnetic particles "like a thickly clustered crowd of people standing in a field," he says. Maxell has developed a perpendicular high-density disk that allows 100K of data per inch, almost a tenfold storage increase over current recording densities. The company has worked with Hitachi to develop a metal-ferrite recording head that provides better head surface contact to read the densely packed particles. Other companies, chiefly Sony, Toshiba, and Matsushita, have issued technical papers and developed prototypes. But don't expect to see the perpendicular disk on store shelves for awhile. Perpendicular recording has been on the drawing boards for several years, but still hasn't proven to be as cost effective or as easily produced as traditional magnetic media, says Maxell's David Berry.

"There continues to be a lot of work by the media and drive people; however, the progress has been much slower than anticipated," he says. "It's a new technology, and the big thing today is the cost of storing per byte on any sort of media. It's a price-performance question right now as to whether it can be made cost effective. We feel that, down the road, it will be the media and drive of the future."

James Porter, head of the market research company, Disk/Trend, Inc., agrees that there's plenty of work ahead before perpendicular recording is durable and cost efficient enough to work.

Stripped-away views of two new 31/2-inch Winchester-style 30- and 20-megabyte hard-disk drives from Peripheral Technology, Inc. Unlike floppies, these hard disks are nonremovable media.

On another front, computer users are finding that Winchester-style hard disk drives are increasing in performance as they drop in price. Lower prices and ease of use—especially important with today's increasingly integrated, memory-hungry applications—are making hard disks attractive even to casual computer users.

A hard disk spins within a drive, much like a floppy, but at faster speeds (3,600 rpm, for example). However, hard disks have traditionally been nonremoveable, and their recording heads don't actually touch the disk—instead, they float just above the surface. In the past, hard disks also cost thousands of dollars, were quite sensitive to dust and smoke, and were prey to "head crashes" that could ruin the whole disk.

Improvements in technology are now bringing prices down, sometimes well below a thousand dollars. In addition, new 31/2-inch hard drives are being introduced along with the standard 8-inch and 51/4-inch models. These new systems are less prone to head crashes, have fewer problems with dust and smoke, and pack as much data into their systems as the older models.

Prices for hard disks in the 10-or 20-megabyte capacities range from $400 to $1,500 depending on access time, capacity, and other features. Some 300,000 of the 3½-inch hard drives were shipped in 1985, while about three million 5¼-inch hard drives (under 30 megabytes) shipped worldwide during the same period. The numbers for 3½-inch hard disks should increase appreciably during 1986, notes Porter.

A new hybrid data storage device for IBM PCs and compatibles, the Clasix DataDrive Plus Series from Reference Technology combines a 550-megabyte CD-ROM optical disc player in the same box with a 10- or 20-megabyte Iomega Bernoulli Box removable magnetic cartridge.

Related to hard disk drives is a relatively new product, the Bernoulli Box from Iomega Corp. The Bernoulli Box actually floats its disk on a cushion of air within the drive, and also allows the disk to be removed—hence, it offers the portability of a floppy with the storage capacity of a hard disk. The floating disk also cuts down on the potential for destructive head crashes and the problems of dust and smoke.

Some computer experts believe that by the year 2000, the days of magnetic computer data storage may be only an historical footnote. Major advances in the use of low-power lasers in audio and video players are being quickly applied to computer technology. One of the hottest consumer electronics items in recent years is the audio compact disc (CD). And later this year, computer users will get a chance to see what CD laser technology can do when linked with a computer—virtually any computer—as a CD-ROM storage device.

The basic principle of CD ROMs is similar to the audio CD. A low-power laser beam reads microscopic pits that have been burned into the disc itself. These pits—representing a series of ones and zeros—contain the data that in a magnetic medium would be formed by the arrangement of magnetic particles. The 4.7-inch CD-ROM discs contain a whopping 550 megabytes of data per disc. The first applications are likely to be encyclopedias, such as the nine-million-word Academic American Encyclopedia, a 21-volume reference work that fits on just a quarter of one CD-ROM disc.

The biggest problem with CD-ROM technology at this point is that the devices are read-only. Unlike the magnetic particles on a floppy or hard disk, once the pits are burned into the surface of a CD, they can't be altered. But that limitation is already being challenged in the labs.

Sony recently announced a writeable 12-inch optical disc system that can hold up to 3.2 gigabytes of information. The disc is composed of two metallic elements sealed in a polycarbonate plastic. The laser beam writes information on the disc by turning the elements into an alloy which has different reflective properties. "This directseal method is more reliable and less costly than melt-type or bubble formation methods, which form gases during the writing process," says Robert Mesnik, Sony Information Products product manager. "The direct-seal method has a simple structure with no air spaces which can cause degradation of information over time."

This is a form of WORM (Write-Once, Read-Mainly) storage technology which offers high-density storage options for a variety of markets. The next step, however, is to create an optical technology that allows a laser to repeatedly write information on the same disc. Although not yet fully developed, an eraseable, reuseable 5¼-inch optical disc has been announced by Maxell for distribution in 1987. But for now, CD-ROMs will remain read-only reference and archival storage devices.

One of the first CD-ROM models debuting in 1986 is Toshiba's XM-1000 drive, which will be able to access digital computer data and also play music—that is, it will be both an audio accessory and a computer peripheral. The unit will have a storage capacity of 600–680 megabytes and may enter the retail market at close to $1,000. Sony will also market its CDU-1 CD-ROM player in 1986.

Five years ago, few computerists could have predicted how fast and how far data storage devices would come by the mid-1980s. Just as microcomputers themselves continue to grow in capability and diminish in price, so too will their storage devices expand to accommodate bigger memories, more complex integrated software, and as-yet unheard of applications.