This is the internal 5¼-inch floppy disk drive for the Commodore 128D. It is able to read a double-sided, double-density disk without any need to flip the disk over.
Disks used in such a fashion could hold up 340 KB of data.
Apple DOS was the disk operating system for Apple II systems, handling read and write operations for floppy diskettes. It was designed to work with Applesoft BASIC.
The 5" monochrome CRT display for the Osborne 1. The screen displayed 52 characters in 24 rows. However the display could present 128 characters at a time; the user needed to use the cursor keys to display characters beyond the current 52 onscreen.