As the cost of media went down, and double-sided drives became the standard, "flippies" became obsolete.
Later, double-sided drives, with heads to read both sides of the disk, became available from third-party companies.
It has a Centronics printer port and a single density floppy interface for up to 4 single-sided or 3 double-sided drives.
The Bondwell-16 had CP/M 3.0, one double-sided drive and a hard disk drive with a capacity of a bit less than 10 MiB.
The DFS does not directly support double-sided discs; instead, the two heads of a double-sided drive are treated as two separate logical drives.
Support for the new double-sided drives was added, allowing 320 kB per disk.
Tandon introduced a double-sided drive in 1978, doubling the capacity, and a new "double density" format increased it again, to 360 KB.
It had two half-height ("thinline") double-sided 8-inch floppy drives, though the Model II upgrade did not replace the floppy drive.
DOS 4.0 used blocks instead of single sectors, and supported single, enhanced, and double density, as well as both single- and double-sided drives.
Later, Billings founded Caldisk Inc. which was instrumental in the development the "double-sided floppy drive".