You’ve got yourself a great little machine there. Osborne 1s are awesome. Does it have the double-density upgrade installed?

Also, I’d like to see some of the date codes on the chips inside of it. My serial A4344 unit has parts from late ‘81 and early ‘82.

There is also a filter cap that likes to blow in the power supply. Make sure to at least remove that before using it.

Edit: I see that you have the 80-column Screen-PAC option installed (you can tell because of the composite video connector next to the “BATT” connector), so you probably have the double-density board as well.