AARD Code, or how Bill Gates finished off the competition

IIRC an explanation for this that I read was that the beta release was given to outside testers and journalists writing about it in computer magazines. Some of those journalists would try to run it on DR DOS, get the intimidating error message and be very helpful in spreading the rumor that it doesn't work properly on DR DOS. The final release would work of course and not have a "smoking gun" in it, but the rumor is out there. The later part obviously failed by only disabling, but not removing the code.

On the other hand of the spectrum you have explanations like the one on Larry Osterman's blog, that this was all for compatibility, because early Windows and the DOS underneath would have to interoperate closely and Microsoft would take the blame if anything didn't work properly[1]. Which by the way is also the reason for gems like [2], which could also be re-interpreted as trying to weed out MS DOS clones.

Of course, the first one is only hearsay because I can't track down the source right now, and BOTH statements are from people who also have a stake here, but on opposing sides, so please take both with a grain of salt. It is not necessary that one side is blatantly lying (or falsely accusing). There can easily be truth to both here, with the "compatibility checks" done for semi valid engineering reasons while also having the desired side effect that management wants of making the competition look bad.

[1] https://docs.microsoft.com/en-us/archive/blogs/larryosterman...

[2] https://news.ycombinator.com/item?id=20315453

Stac electronics made some software (Stacker) which compressed your files on the fly, it was very popular in the early 90s, as it could massively increase the amount of non-program space you had on your 40MB hard drive, if 30M was used for applicaitons/OS and 10M for documents, it would give you another 20-40MB of space, tripping or more the free space you had.

The program sold for something like $100-200 a copy, but as a 40M hard drive was nearer $1k this was a bargain. Stac Electronics was valued as $12/share at the time.

Microsoft saw this, and wanted it. So they sent in their lawyers to make Stac electronics an offer they couldn't refuse. License Stacker to Microsoft and get paid $0.00 down, and $0.00 per copy.

Stac refused the generous microsoft offer, so Microsoft copied {or bought from another company which had copied} their technology (infringing Stac's patents) and bundled it with Dos 6, something called "DoubleSpace" (it was also a buggy implementation).

Drive compression was important at this time. Gates wore a t-shirt with "We came, we saw, we doubled" on at the Dos 6 launch - it's amazing to think now, but 30 years ago every byte counted, Stac's software saved people a fortune in hardware costs, and the killer feature of dos 6 was compression.

Stac's share price collapsed from $12 to $3 practically overnight.

Microsoft were sued, and they lost. They had to pay about $5 per copy of Dos that had been sold to Stac. Dos 6.21 was released which removed Doublespace, and 6.22 reimplemented the technology as 'drivespace'. This eventually came down a little during appeals when the companies settled out of court (there was a more minor case against Stac for using trade secrets), Stac got about $90m in the end.

Either way, Stac was dead. They fought Microsoft, and despite winning the battle, they lost the war. Stac dissolved in 2002.

Maybe my understanding of endianness is off but isn’t it AaRR -> RRAa?