I think it is worth noting that these patents weren't good at all for competition. Stac Electronics proved to be in no way capable of competing with MS Excel, pivot tables are technically not that hard and the lawsuit might have stopped MS bringing them to a huge number of people faster.
They did nothing much, and if they'd done more they'd have retarded progress.
Oh they made a disk compression program. Happily, the argument stays almost exactly the same - substitute NTFS for MS Excel. The reason I like that anti-patent argument is because, as far as I've seen, it applies to literally everything in software outside some ultra-niche applications of software that only handfuls of companies use.
The patents from that era were largely junk (famously, Amazon had a patent on having a button that you clicked to buy something). They're all for basic techniques that were going to get figured out one way or another. They were most useful as a tool for stamping on other companies that were figuring out the same techniques at about the same speed for the same reasons. IE, were no use at all for spurring innovation. The idea that MS should owe some company $100 million because they used a specific compression algorithm is serious because of the amount of money it cost them but otherwise stupid.
They did nothing much, and if they'd done more they'd have retarded progress.