Vectrex (without the definitive article) was a very clever idea which was killed off by the 1984 video games crash, although it's hard to see how it could have survived into the age of Super Mario Brothers. It cost $199.99 in the US in 1983 and didn't really have a chance to become popular, whilst it was discontinued less than a year after it was released in the UK.

I once saw two at a car boot sale for fifty pounds each, in the late 80s. They're worth slightly more than that nowadays, although if you want to play the games ('Armour Attack' and 'Web Wars' are quite good, being clones of 'Combat' and 'Tempest' respectively) an emulator is available.

The Vectrex itself was a console that, uniquely, had a proper vector display built-in. Vector displays don't build up the image with pixels, as with a conventional television or monitor, they actually draw the image with individual lines - if you ever played the old 'Star Wars' or 'Battlezone' arcade machines you'll recognised the visual style. The end result is that vector graphics don't look jagged, but are hollow. Vector monitors have a habit of overheating and catching fire, although the Vectrex did not suffer from this problem.

The Vectrex' joysticks were analogue, and two could be plugged into the console. The built-in game was a clone of 'Asteroids'. The display was strictly black and white, although there were colour overlays that could be put over the screen to tint certain areas. For whatever reason, the screen was taller than it was wide. It all resembled the evil twin of an Apple Macintosh.

The free Vectrex pen is probably quite valuable nowadays.