Apple /// computer.
This is an Apple III 128k that has been upgraded to 256kB.
Serial is 51733 probably made around 1980-81.
It has a power supply that can be switch between 110V and 220V (currently 110V).
This Apple III passes the initial memory check and boots. The diskdrive works with about half of the floppies I’ve tested with so it probably need some adjustment to work better. The keyboard is clean and all keys works. The case has a (almost invisible) crack in the top right (see picture) and a couple of glued (not visible) parts inside but looks OK. This overall condition of this machine is OK, but not perfect.
The monitor in the picture is sold separately.