I heard about, purchased, and read this fascinating book Track Changes: A Literary History of Word Processing, by Matthew G Kirschenbaum. It tells the history of word processing on computers, but primarily from the viewpoint of the writer. This is a scholarly work with 80 pages of footnotes!
Using a computer instead of a typewriter (or handwritten manuscripts) was earliest adopted by science-fiction authors. That should be no surprise. How and why authors adopted the computer, what they bought, and how they used them is the primary content of this book.
Check it out here: https://www.amazon.com/Track-Changes-Literary-History-Processing/dp/0674417070/ref=sr_1_2?crid=15QWE7SF11Y65 and, no, I don’t get any referral fee.
I used word processing on computers as far back as the mid 1970’s to document my work. Most engineers would write reports and then have the department secretary (yes, there was such a person back then) type it up. My handwriting has always been atrocious so I would type my reports in the evenings using the secretary’s typewriter. As soon as we had a computer available, I switched to entering my documents into text files (primary using the TECO text editor) and printing them out. Eventually there was also word processing software that would format the documents for me. All of this was done on minicomputers and mainframe computers, not on personal computers or dedicated word processors.
My father started a family newsletter in 1975, and in 1979 I took over layout and printing. That first effort can be seen here: https://almy.us/news/Newsletters/No017.pdf
After a few years he bought a personal computer and took back the chore. He continued to produce the newsletter for 31 years, stopping after my mother died.