I recently got a (signed!) set of manuals for the “Microsoft Z-80 SoftCard” that were originally provided to the designer of the SoftCard, Don Burtis, for the purpose of proofing the text. They are interesting in that they contain some penciled corrections, and also that the product itself was called the “Z-80 SoftCard.”
Sometime after this, but before the product hit the market, Zilog asked Microsoft to remove the “Z-80” from the name, and the card was actually sold just as the Microsoft SoftCard. For comparison, here are those manuals:
I scanned the manual as it was, for the historical interest, and if you’re curious about what corrections were penciled in, I’ve noted all those that I saw in the table of contents of the PDF. Mostly they are correcting technical typos.