From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
The 21 MB Floptical 3½-inch disk

Floptical refers to a type of floppy disk drive that combines magnetic and optical technologies to store data on media similar to standard 3½-inch floppy disks. The name is a portmanteau of the words "floppy" and "optical". It refers specifically to one brand of drive and disk system, but is also used more generically to refer to any system using similar techniques.

The original Floptical technology was announced in 1988[1][2][3] and introduced late in 1991[citation needed] by Insite Peripherals, a venture funded company set up by Jim Adkisson, one of the key engineers behind the original 5¼-inch floppy disk drive development at Shugart Associates in 1976. The main shareholders were Maxell, Iomega and 3M.

Technical aspects[edit]

The technology involves reading and writing data magnetically, while optically aligning the read/write head in the drive using grooves in the disk being sensed by an infrared LED and sensor (a form of visual servo).[4] The magnetic head touches the recording surface, as it does in a normal floppy drive. The optical servo tracks allow for an increase in the tracking precision of the magnetic head, from the usual 135 tracks per inch to 1250 tracks per inch. Floptical disks provide 21 MB of storage. The drive has a second set of read/write heads so that it can read from and write to standard 720 kB and 1.44 MB (1440 KiB) disks as well.[4][5]

To allow for a high degree of compatibility with existing SCSI host adapters, Floptical drives were designed to work as a standard floppy disk drive, and not as a removable hard disk. To ensure this, a "write lockout" feature was added in the firmware. This effectively inhibits writing (including any kind of formatting) of the media. It is possible to unlock the drive by issuing a SCSI Mode Sense Command, 1A 00 20 02 A0. It is unclear how much of a problem this is, and Insite also issued EPROMs where this "feature" was not present.

At least two models were produced, one with a manual lever that mechanically ejected the disc from the drive, and another with a small pinhole into which a paperclip can be inserted, in case the device rejected or ignored SCSI eject commands.

Technical specifications[edit]

Unformatted 25 MB
Formatted 20385 kB
Rotational speed 720 rpm[5]
Track density 1250 TPI[5]
Recording density 23980 bpi (RLL)[5]
Transfer from disk 1.6 Mb/s[5]
Buffer transfer rate 2 MB/s[5]
Average seek time 65 ms[5]
Settle time 15 ms[5]
Motor start time 750 ms[5]
Number of heads 2[5]
Cylinders 755[5]
Sectors per track 27
Sector size 256, 512, or 1024 bytes (set at format time)
Interface SCSI

Market performance[edit]

Insite licensed the floptical technology to a number of companies, including Matsushita, Iomega, Maxell/Hitachi and others. A number of these companies later formed the Floptical Technology Association, or FTA, to try to have the format adopted as a replacement of standard floppy disks.

Around 70000 Insite flopticals are believed to have been sold worldwide in the product's lifetime. Silicon Graphics used them in their SGI Indigo and SGI Indy series of computer workstations. It was also reported that Commodore International had selected the Insite Floptical for its Amiga 3000.[6] However, this did not take place, and while Flopticals were installed in many Amiga systems, they were sold by either Insite, TTR Development or Digital Micronics (DMI), and not bundled by Commodore.

Iomega licensed the floptical technology as early as 1989 and produced a compatible drive known as the Insider.

A few years later a number of other companies introduced floptical-like but incompatible systems:

Iomega introduced their own ZIP-100 system storing 100 MB in 1994, which would go on to sell into the tens of millions. Later versions would increase the capacity to 250 and 750 MB.

Another similar system was Imation's LS‑120 SuperDisk in 1996. The LS-120 stored 120 MB of data while retaining the ability to work with normal 3½-inch disks, interfacing as a standard floppy for better compatibility. A later LS-240 version would store up to 240 MB.

A smaller competitor was the almost unknown Caleb UHD144 in 1997.

Since 1998 Sony also tried their own floptical-based format, the Sony HiFD, but quality control problems ruined its reputation. The first version could store 150 MB, but it was soon replaced by a 200 MB version.

There was serious consideration that one of these systems would succeed where the Floptical failed and replace the standard floppy disk outright, but the rapid introduction of writable CD-ROM systems in the early 2000s made the market disappear.

Operating system support[edit]

Support of Floptical drives is present in all Microsoft Windows NT operating systems up to Windows 2000, where it figures as 20.8 MB drive format option in the FORMAT command options. The FORMAT command in Windows XP and newer lacks support of the Floptical drive.[7] Floptical support exists in SCO OpenServer as well. SCSI-equipped Macintosh computers could boot from a Mac operating system installed on a floptical; a formatting utility application was provided to erase and format floptical disks. Likewise, Silicon Graphics's IRIX operating system includes floptical support.

See also[edit]


  1. ^ Webber, Julie (1988-08-15). "Insite's "Floptical" Drive to Increase Storage Capacity". InfoWorld: 6. Retrieved 2012-01-20.
  2. ^ Kotkin, Joel (1988-09-01). "The Return of the Floppies - Floppy disk drive company looks to innovate to compete with Japanese manufacturers". Inc. Retrieved 2017-06-19.
  3. ^ Brownstein, Mark (1988-09-12). "High-Capacity Floppies are Drives of the Future - Experts See 100MB Capacity". InfoWorld: 27, 30, 32. Retrieved 2017-06-19.
  4. ^ a b Pollack, Andrew (1990-03-14). "The Evolution of the Floppy Disk for PCs". The New York Times. Business Technology. Retrieved 2017-06-19. […] The Brier and Insite systems, which can store 20 megabytes, increase the number of tracks. […] The key to […] the Brier and Insite drives […] is that information is embedded in the tracks themselves and acts as a homing signal, keeping the head on the track. In Brier's Flextra system, a low-frequency magnetic homing signal is embedded at the bottom of the barium ferrite coating after the disk is manufactured. Later, the data are recorded in the top of the layer, using a higher-frequency signal. The Brier system cannot read and write lower-capacity disks, although the company says it will introduce a model that can do that later this year. Insite's Floptical disks, which can store 20.8 megabytes, use homing technology similar to that used in optical disks. Microscopic grooves are stamped into the diskettes at the time the disks are made. A light-emitting diode rides along with the magnetic head and shines light into the groove, which is reflected and received by a photo-detector. If the head starts to sway from the track, the light will miss the groove and the reflection will change, alerting the system to adjust course. While the tracking is optical, the data are recorded magnetically in tracks between the grooves. To achieve compatiblity with existing lower-capacity drives, the system uses two magnetic recording heads - one to read the high-capacity diskettes and the other to read conventional diskettes. […] Brier has designed its system from scratch to achieve higher speeds. Insite uses a conventional floppy drive and homing components that are used in compact disk players. […]
  5. ^ a b c d e f g h i j k ""Floptical" drive info". 1990-01-17. Archived from the original on 2017-06-19. Retrieved 2017-06-19. […] INSITE I325/I325VM: CAPACITY unformatted 25 megs, formatted 20.8 megs, Recording density 23980 BPI (RLL), Transfer from DISK 1.6 Mbit/Sec, Buffer transfer rate 2 Mbyte/Sec, Average Seek time 65 msec, Settle time 15 msec, Motor start time 750 msec, # of read/write heads 2, Track density 1250 TPI, Cylinders 755, Tracks 1510, Rotational speed 720 rpm, Power dissipation 6 watt average, Data reliability <1 error unrecoverable error per 10^11 bits, Seek errors <1 error per 10^6 seeks, Drive dimensions H: 1.625" W: 4.0" D 5.91", […] SCSI […] Common Command Set (CSC), soft formatting, error checking and correction (ECC), and defect mapping. In addition, the I325VM (variable mode) offers FULL READ AND WRITE DOWNWARD COMPATIBILITY with current 3.5 inch 720 kB and 1.44 MB formatted diskettes. […] Brier Technology Flextra BR 3020: CAPACITY unformatted 25.0 meg, formatted 21.4 meg, CONFIGURATION Number of disks 1, Data Surfaces 2, Data heads 2, Servo System T^3, Tracks per surface 516, Track density (TPI) 777, Track capacity (bytes typical) 20480, Blocks per drive (512 byte) 42080, Blocks per surface (512 byte) 21040, Blocks per track (typical 512 byte) 40, MEDIA (flexible diskette) 3.5", PERFORMANCE Actuator, Linear voice coil motor, Seek time (includes setting), Track to track (ms) 15, Average (ms) 35, Maximum (ms) 70, Average latency (ms) 41.6, Rotation speed (RPM) 720, Data transfer rate, To/From the media (megabits/sec) 2.2, To/from the buffer (megabytes/sec) 1.25, Start time 1 sec, Stop time 1 sec, READ/WRITE, Interface SCSI, Recording method BRLL, Recording density (BPI) 26000, COMPATIBILITY, the BR3225 (not BR3020) reads IBM formatted floppy disks, Dimensions, L: 5.75", W: 4.0", H: 1.625" Weight: 1.6 pounds, Power requirements (*), DC Input +12 volts DC, +5 volts DC, Power dissipation <9 watts (operational-seeking), Power management algorithms reduce power to an average of 2.0 watts […]
  6. ^ Bixby, Robert (November 1991). "The flop's a hit. (floptical technology)". COMPUTE!. Archived from the original on 2017-06-19. Retrieved 2017-06-19.
  7. ^ "Lack of Floptical support in Windows XP". Microsoft. Retrieved 2007-09-12.

Further reading[edit]