Floppy Disc Replacements

With today’s hard disks measured in gigabytes, and with multimedia and graphics file sizes often measured in tens of megabytes, a capacity of 100MB to 150MB is just right for taking over the traditional functions of a floppy disk – moving a few files between systems, archiving or backing up individual files or directories, and sending files by mail. It’s not surprising, then, that drives in this range are bidding to be the next-generation replacement for floppy disk drives. They all use flexible magnetic media and employ traditional magnetic storage technology.

Without doubt, the most popular device in this category is Iomega’s Zip drive, launched in 1995. The secret of the Zip’s good performance (apart from its high 3,000rpm spin rate) is a technology pioneered by Iomega (based on the Bernoulli aerodynamic principle) which actually sucks the flexible disk up towards the read/write head rather than vice-versa. The disks are soft and flexible like floppy disks, which makes them cheap to make and less susceptible to shock.

The Zip has a capacity of 94MB and is available in both internal and external versions. The internal units fit a 3.5in bay, come with a choice of SCSI or ATAPI interface and are fast, with an average 29ms seek time and a data transfer rate of 1.4 KBps. External units originally came in SCSI or parallel port versions only. However, the Zip 100 Plus version, launched in early 1998, offered additional versatility, being capable of automatically detecting which of these interfaces applied and operating accordingly. The range was further extended in the spring of 1999 when Iomega brought a USB version to market. In addition to the obvious motivation of Windows 98 with its properly integrated USB support, the success of the Apple iMac was a key factor behind the USB variant. Apple’s somewhat bizarre decision to omit a floppy drive had left people crying out for a removable storage option – and, of course, iMacs sport USB ports as standard.

Any sacrifice the external version make in terms of performance is more than outweighed by the advantage of portability – making the transfer of reasonable sized volumes of data between PCs a truly simple task. The main disadvantage of Zip drives is that they are not backward compatible with 3.5in floppies.

The end of 1996 saw the long-awaited appearance of OR Technology’s LS-120 drive. The technology behind the LS-120 had originally been developed by Iomega, but was abandoned and sold on to 3M. The launch had been much delayed, allowing the rival Zip drive plenty of time to become established. Even then, the LS-120 was hampered by a low-profile and somewhat muddled marketing campaign. Originally launched under the somewhat confusing brand name a:DRIVE, the LS-120 was promoted by Matsushita, 3M and Compaq and was initially available only ready-installed on the latter’s new range of Deskpro PCs. Subsequently, OR Technology offered licences to third-party manufacturers in the hope that they would fit the a:DRIVE to their PCs instead of a standard floppy.

However, it was not until 1998, when Imation Corporation – a spin-off of 3M’s data storage and imaging businesses in the summer of 1996 – launched yet another marketing offensive under the brand name SuperDisk, that the product begin to meet with any serious success in the marketplace.

A SuperDisk diskette looks very similar to a common-or-garden 1.44MB 3.5in disk, but uses a refinement of the old 21MB floptical technology to deliver much greater capacity and speed. Named after the laser servo technology it employs, an LS-120 disk has optical reference tracks on its surface that are both written and read by a laser system. These servo tracks are much narrower and can be laid closer together on the disk: an LS-120 disk has a track density of 2,490tpi compared with 135tpi on a standard 1.44MB floppy. As a result, the LS-120 can hold 120MB of data.

The SuperDisk LS-120 drive uses an IDE interface rather than the usual floppy lead. This uses up valuable IDE connections, so with an IDE controller which only supports two devices, rather than an EIDE controller which supports four, this represents a potential problem. While its 450 KBps data transfer rate and 70ms seek time make it of the order of 5 times faster than a standard 3.5in floppy drive, its comparatively slow spin rate of 720rpm mean that it’s not as fast as a Zip drive.

However, there are two key points at the forefront of the LS-120 specification and which also represent its principal advantages over the Zip. First, there’s backward compatibility: as well as the 120MB SuperDisk diskettes the LS-120 can also use standard 1.44MB and 720KB floppy disks which are handled with a 3-fold speed improvement compared with a standard floppy drive. Second, compatible BIOSes allow it to act as a fail-safe start-up drive in the event of a hard disk head crash. Taken together these make the LS-120 a viable alternative to a standard floppy drive.

Early 1999 saw the entry of a third device in this category with the launch of Sony’s HiFD drive. With a capacity of 200MB per disk, the HiFD provides considerably greater storage capacity than either Iomega’s 100MB Zip or Imation’s 120MB SuperDisk drive. Initially released as an external model with a parallel port connector and a pass-through connector for a printer, Sony also planned internal IDE and SCSI models for later in 1999. Compatibility with conventional 1.44MB floppy disks is provided by equipping the HiFD with a dual-head mechanism. When reading 1.44MB floppy disks, a conventional floppy-disk head is used. This comes into direct contact with the media surface, which rotates at just 300rpm. The separate HiFD head works more like a hard disk, gliding over the surface of the disk without touching it. This allows the HiFD disk to rotate at 3,600rpm and a level of performance that is significantly better than either of its rivals. However, the HiFD suffered a major setback in the summer of 1999 when read/write head misalignment problems resulted in major retailers withdrawing the device from the market.