Duo Disk

In 1983, along with the introduction of the Apple IIe, Apple initially offered a combination of two, two third-height, 143K Disk II drive mechanisms side-by-side in a single plastic case, called the DuoDisk 5.25 (A9M0108), which could not be daisy chained. The unit was designed to be stacked on top of the computer, and beneath the monitor. Each unit required its own disk controller card and the number of units was limited to the number of available slots. Originally released with a DB-25 connector, to match that of the Apple III Plus, it was the first to adopt Apple's standard DB-19 floppy drive connector.