Epson PF-10 portable 3,5" floppy disk unit

Floppy disk drive, 1984, Epson. The PF-10 is a battery-powered external 3.5" floppy drive for the Epson PX-8 Geneva and PX-4 portables, connected through the high-speed serial link of the computer. It stores 320 KB on each disk and has its own rechargeable battery, so the whole system could work away from mains power; the drive contains a Z80 and its own ROM to handle the disk format.