Micropolis 100163-51-8 is a floppy disk controller board, implemented on a 5-by-10-inch PCBA
that plugs into the S-100 bus.
Following the success of the 100085
controller card, Micropolis refined
its floppy controller cards and marketed these advanced cards as the Miropolis Intelligent Controller
Sometimes it was marketed as Micropolis 1071
100163 is the base model number and suffixes designate which version of the controller it
100163-51-8 is for 100TPI drives, GCR encoding and dual heads.
100163-52-6 is 100TPI, GCR, single head
100163-53-4 48TPI, MFM, dual head
100163-54-2 48TPI, MFM, single head
100163-55-9 100TPI, MFM, dual head
100163-56-7 100TPI, MFM, single head
This controller could be used with a Micropolis 1015
or Micropolis 1115
OEM drive. Also, it is usually shipped
with Micropolis floppy-disk storage subsystems, which use these OEM drives internally, like the earlier Micropolis 1055
or 1043, 1053 subsystems. A 1055 subsystem, for example, is comprised of two drives with two read/write heads each - but they
share one controller. Further, up to four 1055 subsystems can be daisy-chained to one common controller card.
A unique feature is the 100163-51-8's ability to employ Group coded recording
for data storage on the disk medium. GCR in short is data being frequency modulated in a run length limited (RLL) encoding scheme
combined with error-correction. This way, more data can be packed on disk (areal density) and reading/writing is faster.
A single-sided double-density disk, formatted with Micropolis 77-tracks (at 100TPI) usually stores 630,000 bytes. With GCR this
can be increased to 946,000 bytes single-sided and even 1,892,000 bytes of file space on a double-sided disk.