AFAIK, WordStar never ran directly on the Apple II. You must've had a CP/M card, probably the Microsoft Z-80 SoftCard. And I'll bet that 80 column card was a Videx. I eventually switched from WordStar to AppleWorks. Somehow, I never used Apple Writer.

https://en.wikipedia.org/wiki/Z-80_SoftCard

https://www.wiseowl.com/articles/a2fpga-videx-01-the-card-th...