DRIVE SERIES SPECIFICATIONS
FLEXIBLE DISK DRIVE SPECIFICATIONS - 1015 SERIES
The Micropolis 1015/1016 series of OEM floppy disk drives consists mainly of drive mechanics assemblies meant to be
installed in an OEM drive enclosure. But for end-users and smaller OEMs, Micropolis also offered a ready-to-use
drive+enclosure model with the Micropolis 1055
, a so called "subsystem".
The earliest entry in the drive family is the single-sided 1006
, which was available as single (roman numeral II)
and double sided variant (roman numeral IV). (Note that on drive model stickers, roman numerals like "II" are usually written
as arabic "2".) It has a relatively open black frame, where the disk "clamp mechanism" with its wedge shape can be easily
recognized. An "LMS" stepper motor manufactured by MOLON motor & coil co. is used and placed at the far end of the assembly,
next to the belt drive motor located on the left (seen top down) backside.
The revised and improved update of these drives was named 1106 (not 1016). These updated drives labeled 1106 II and 1106 IV
were also nicknamed "Micropolis Safari drives". In comparison with earlier model 1006, the 1106 drives are assembled on an
aluminum die cast chassis, which results in improved rigidity of the drive. Of both versions 1006 and 1106, Commodore
International was an important customer, installing these drives OEM in Commodore 8050 and 8250
floppy disk subsystems.
A next iteration are drives labeled as 1015 and 1016 which came in model variants identified by roman
numerals I, II, V and VI, each with a different combination of track stepping, head number and data encoding type (MFM / GCR).
Although naming might imply that drives from the Micropolis 1115-Series
are closely related, 115
drives were introduced years later and represent a bigger step forward.
Later models and especially the 77-track drive variants (subsequently the family as a whole) have been marketed as
Following the success of the 100085
the "MegaFloppy" family was Micropolis' first iteration of actual drives and drive-subsystems in 1977/1978. It was
followed by the 1040/1050 subsystem series
around 1980 which used the 1015 drive series
in "MacroFloppy" (35 tracks) and "MetaFloppy" (77 tracks) variants.
MOD I drives have a track density of 48 tracks per inch (TPI) with a total of
35 tracks. MOD II drives have a track density of 100TPI with 77 total tracks.
The difference in track density and total tracks results from using a different lead screw in the positioner,
a different read/write/erase head, and different components and adjustments on the PCBA.
In 1980, when the market for "quad density" 5.25-inch floppy disks
moved towards the 96TPI standard instead of the Micropolis proposed 100TPI, the 1015 series
forked a line
of 96TPI drives. Models 1015-5 and 1015-6 (stylized with roman numerals as 1015-V and 1015-VI) are FM/MFM encoding
drives with one or two read/write heads and Micropolis models 1016-5 and 1016-6 are GCR encoding drives with one or
two read/write heads respectively.
Floppy disk media used to be manufactured as hard-sectored and soft-sectored. Read more about hard-sector and
in the Knowledge base. Within the drive's mechanics a photosensor circuit is used to detect
the occurrence of the diskette's index mark (and sector marks, if present ). But the drive's mechanics and electronics
are agnostic towards these marks as the interpretation is delegated to the host controller. In operation, the drive's
sector/index photosensor circuit will generate a signal for each hole passing the disk's window. The host controller
must be able to differentiate the index hole from the sector holes and incorporate these signals into its logics.