Analysis of information sources in references of the Wikipedia article "Floppy disk variants" in English language version.
6848 cylinders × 36 blocks/cylinder × 512 bytes.
[…] 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 compatibility 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. […]
A consortium of manufacturers led by Matsushita introduced this 3-inch-wide Compact Floppy format in 1983 to compete with Sony's 3.5-inch floppy system. The Compact Floppy, which held about 140KB per side, saw the most use in British Amstrad computers; otherwise, the format faded quickly into history's back pages.
[…] 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 […]
A consortium of manufacturers led by Matsushita introduced this 3-inch-wide Compact Floppy format in 1983 to compete with Sony's 3.5-inch floppy system. The Compact Floppy, which held about 140KB per side, saw the most use in British Amstrad computers; otherwise, the format faded quickly into history's back pages.
[…] 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 […]
6848 cylinders × 36 blocks/cylinder × 512 bytes.
