How did company employees work in the old days? Vol. 1

I was watching the anime "Sazae-san" with my 5-year-old son on Sunday. There was a scene where Namihei receives a call at work from his grandson, Tara-chan. While on the phone, Namihei picks up a pencil and writes something in a notebook. There's almost nothing else on his desk besides the phone and notebook. This made me wonder, "How did office workers do their jobs in the old days?" Without computers or the internet…
The original "Sazae-san" is set roughly between the 1945s and 1960s, and even the anime version depicts a culture that seems to have mostly stopped evolving in the 1980s (though the anime officially claims to always depict "the present," occasionally featuring cell phones or Tokyo Skytree).
The reason I had this question was because I've recently been thinking, "Is work only what we do using computers and the internet?" I'm also experiencing digital fatigue. Slack and Chatwork messages come in constantly, and balls are tossed around endlessly in task management tools.
Since I can work from home, I sometimes find myself checking chats even after work hours.
Even with all this digital, remote, SaaS, and automated work, there must be an "origin" from before things were digitized.

A story I heard from my uncle, who used to work for a textile manufacturer.

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Risograph printing
Paper Cover: Kuchen / Body: Medium quality paper
32 pages / A5