"Atari Inc. had lent $500,000 to Amiga Corporation in 1984... Amiga was purchased in August 1984 by Commodore for $27 million -including paying off the Atari loan." [0]

So in an alternate possible reality, Amiga could have been released as an Atari brand.

[0] https://en.wikipedia.org/wiki/History_of_the_Amiga#Amiga_Cor...

Amiga was founded by Jay Miner and other ex-Atari people, and Atari was going to buy Amiga until Commodore swooped in.

Jack Tramiel, Commodore's ex-CEO, bought Atari. The Atari ST is very much what a Commodore still led by Tramiel would have introduced: The largest statistics for the lowest cost (ST advertisements really emphasized how little one paid for a 512KB or 1MB computer) and a rudimentary DOS. The Amiga very much reflects its Atari 8-bit heritage: Sophisticated coprocessors for everything, and emphasis on high quality components over low cost.

In an alternative timeline this would have been likely.

The same engineers who worked on the Atari 8-bit home computer architecture went on to create the Amiga, which is also visible in the design decisions (e.g. the 8-bit Atari already had a display-list co-processor similar to the Amiga's Copper).

AFAIK Atari also tried to buy the Amiga company, but Commodore beat them, so Atari had to find an alternative 16-bit design that could ideally be launched ahead of the Amiga. And ironically this 16-bit design (the Atari ST) was designed by (some of) the same people who worked previously on the C64.

I believe the consensus is now that the Tramiels and Shivji were already hard at work on what became the ST ("Rock bottom price" project) before Tramiel discovered the Amiga IP and went after Commodore over it. I don't think the ST was an attempt to catch up with the Amiga so much as the lawsuit with Commodore was an attempt to slow Commodore down. I'm sure they would maybe have tried to bolt Amiga tech later into the ST project if they could have, though. (Makes you wonder if the choice to exclude a Blitter from the original ST has something to do with that...)

As it was the ST beat the Amiga to market by almost a year, and had an initial sales lead until Commodore introduced the A500 and dropped the price a bunch. I know the A1000 wasn't even in the running for me when I bought my ST, it was ridiculously overpriced.

Atari also had a pretty good developer programme for the ST, I don't remember any discounts being available for an Amiga.

There was an odd exchange between Commodore and Atari personnel in the early '80s, with a group leaving from each company to found startups that were ultimately acquired by the other company. Presumably part of the premise of this alternate history is that the conditions leading to this exodus/swap were averted and the new generation was funded and controlled directly by Commodore and Atari.

What eventually became Amiga was originally developed via Atari funding to become Atari's 16-bit offering. Jay Miner, who was the brains behind CTIA/GTIA/ANTIC, was the force behind the Amiga development team, which at time was a small independent company called HiToro.