I bought a JR-100 set off Mercari a few weeks ago. It included a JR-100 computer, the expansion unit, the required dedicated power supply unit for the expansion unit, a few books and manuals, a joystick, and this monitor - the National TR-120M1C. I turned on the JR-100 plugged into the monitor and...

...all was not well. It didn't appear to be any fault of the monitor, though, so I switched the JR-100 of unknown condition with the JR-100 in my collection and things looked up quite a bit. Here is an example of the JR-100's PCG output as well as text, as displayed by this beauty.

It is the first time I've had a monochrome monitor come through my hands. I can't really keep it at this time, but it's a nice monitor. It arrived to me in better condition than I expected. I thought there was a fairly large crack on top of the monitor, but it just turned out to be a big and relatively deep scratch. Cleaning it up had a good effect on the scratch but it's still fairly obvious.

The monitor came with its original manual.

It was made to be paired with the JR-100, but it's just standard composite input, so I tested it with a couple of MSX games, Phantasie IV and Bubble Bobble, as well.