== 16 bit ==
The [[Atari ST]] was released in 1985. The case looks a lot like the 8bit Atari XE. It originally had an external PSU and an external 3.5inch floppy drive. Atari sold single-sided and double-sided (360KB/720KB) floppy drives. The fact that a single-sided floppy drive option existed resulted in games using single-sided 3.5inch floppies for a long time, even supplying two 360KB floppies instead of a single double-sided one.
In 1986, the Atari STF integrated the PSU and a double-sided floppy drive inside the machine itself.