Up to the 1990s there were workstations designed for software development (Lisp/Smalltalk Machines by various vendors), graphics and CAD (Apollo, SGI), and general purpose systems (Sun, HP).
Was Xerox Star the only office workstation?
Were there other dedicated workstations (not high-end PCs or Macs) designed for office and business tasks? Of course there were word processing machines. But I’m not sure they qualify as they didn’t play in the same league as the Star and were much less versatile.
I think something like the Commodore PET might qualify. Back in the day, I saw it used for everything from cash registers to accountants’ workstations, but rarely for anything else.
I think that the original IBM PC was conceived and marketed as a business machine and only grew beyond that because of Microsoft’s deep commitment to it as a platform and IBM’s uncharacteristicly open specifications and design.
If not for that combination, the PC might never have left the office and most of us would have stuck with the companies who were actually breaking new ground, Apple and Commodore.
Do Wangs count? Not sure if they were designed for office/business tasks, but I think they were marketed for office/business tasks.
I feel like most offices would use the general purpose machines.
I am not sure, but I found this article about the history of typewriters & computers that might have the answer some where. https://guides.loc.gov/office-history/typewriters-computers