== 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. In 1986, the Atari STF integrated these components the PSU and a double-sided floppy drive inside the machine itself.
A version intended for business users was also created in 1987 and named the Mega ST. It featured more RAM, a real time clock, a blitter chip for faster rendering and a detached keyboard.