Apple DuoDisk

Background

In 1984, shortly after the introduction of the Apple IIe the previous year, Apple offered a combination of two, two third-height, 140-kilobyte Disk II drive mechanisms side-by-side in a single plastic case, called the DuoDisk (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 (as each card could still control only two drives) and the number of units was thus limited to the number of available slots; in practice, few uses of the Apple II computer can make good use of more than two 5+1⁄4-inch drives, so this limitation mattered little. 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.