Before computer software to produce mathematical typescript, the technology to use was an IBM Selectric typewriter with its changable typeballs. There were two kinds: Selectric II with 88 characters per ball, and the Selectic III with 96 characters per ball. The two sets of typeballs could not be interchanged. Caryn used as Selectric II with 3 typeballs to produce an inkprint draft of her thesis.
The Symbol typeball had the most useful math symbols. Below is a photo of the Symbol 10 typeball and the complete set of characters it produced.
