How big was the original CP/M version of WordStar? As in, the size of the program itself? Presumably it was in the low tens of kilobytes (I don't think it's possible to cram a practical word processor into less than 10K) but I'm interested in an actual figure.
How big was the original CP/M version of WordStar?
The oldest copy of WordStar (or Wordmaster) I could find is 1.01 (but with a date of 1980) sizing
30,080 bytes for WS 20,992 bytes for WSMSGS
Which both seem rather high, as Wordmaster, before being renamed to WordStar, did fit into mere 10 KiB. One of the core features of WordStar was its organization as overlays, thus the used memory might be lower.
I don't think it's possible to cram a practical word processor into less than 10k
That might quite depend on your value for 'practical'. I can quite well think of a full screen word processor that can be cramped in less tan 10 KiB. As said, Wordmaster is just 10 KiB. And DR's TEX (where Wordmaster is somewhat based on) only uses 8 KiB.