Simplify the following text for a Grade 9 native English-speaking person.
Original: Linwood G. Dunn expanded the concept in the 1930s , and the development continued well into the 1980s , when the printers were controlled with minicomputers .
Simplified: Linwood G. Dunn expanded the concept in the 1930s . The development continued well into the 1980s , when the printers were controlled with minicomputers .