About 40 examples of the Type 51 and 51A were produced.
Poland was another country with more than a thousand and East Germany had about 800 examples.
Game contains about 100 examples of logical gates etc. created in Wireworld.
Today there are about 300 known examples left world wide and less than half are in flying condition.
Krabbé wrote a whole article on the caterpillar theme, citing about ten examples.
There were five versions of this button; about 45 examples survive.
There are about 90 examples of the Osborne bull advertisements.
However, with the impact of the Great Depression, sales plummeted, and only about 100 further examples were built over the next eight years.
About 30 examples, some framed, will be on display through Nov. 30.
And this weekend I probably had about four examples of people who came up and said that's exactly what we're doing.