There was a time when there was no industry standard for PC. Every software and hardware had to be created in different versions, one for each PC manufacturer (like iOS and android today).
IBM was so big that all software and hardware makers were targeting IBM computers first.
Backwards compatibility was not usual and it was common for people to have to buy new versions of software and hardware whenever they updated their machine.
Compaq’s idea: make a machine that could run the IBM software/hardware. « IBM compatibe » or « clone ».
Promised 100% compatibilty. 99% was not reliable enough.
Made a machine that was even more backwards compatible than IBM themselves. Keeping backwards compatibility was key.
Started with portable computers so that they didn’t eat into IBM or Apple’s market.
Then IBM started the war by making a portable. Portable was not a success and Compaq’s product succeeded. Then Compaq fired back by releasing a fully backwards compatible desktop.
Compaq then took the innovation lead from IBM by releasing the first 386.
IBM fired back by announcing the PS/2, a completely new architecture that they protected against cloning. 0 backwards compatibilty, they were relying on their brand to push it through.
Compaq organized the rest of the industry (« gang of 9 ») to push for a non-IBM standard that supported backwards compatibility.
Eventually that new standard won and made the industry what it is today.
Compaq selected their market very thoughtfully: started with portable computers so that they didn’t directly enter competition with Apple/IBM. Then only moved to desktop/laptops when the time was right: sometimes later than the competition but always guaranteeing 100% compatibility.
Compaq had a reputation for quality and reliability, which was very different from the Compaq of the 90s that I grew up with, where it already was the low-end market brand.
They changed the industry but that story is nowhere as commonly told as the Apple or Microsoft one.
One of the « secret sauces » of Compaq was « the Process », a way to make difficult decisions. In short: a leader is in charge of guiding a team of experts through a consensus. See p. 93.