Pointless speculation but just for fun - what SMALL thing (or things) do you think Atari could have done to improve the life and success of the original ST? I think we've already seen discussions in the past where people say "it should have had a blitter... and a copper... and a 386DX processor, in built hard drive! 16MB of RAM! Voice activated, and it should have been cheaper!"
So some general guidelines are:
- We are allowed the full use of hindsight which Atari didn't have at the time, so this isn't about scolding Atari or saying they "should have done X". This is about what "could" have been done, given we know where the industry went, what game and business trends occurred. So it could be a small mod that perfectly fits with what we know happened later.
- Shouldn't add more than 10% to the price. I think at launch the 520ST was around $600US in 1985, $999 for the 1040 in Jan 1986. If you add too much to the price you're going into a space that the Amiga 500 covered well in 1987 $699US (although the ST would have been cheaper by then too), and ruin the ST's "power without the price". Back at launch in 1985, of course, the Amiga 1000 was $1295US. But we know we wouldn't have that budget advantage when 1987 came around. So I think the additions shouldn't make the 520ST more than ~$650 in 1985, and not more than $550 by the time 1987 rolled around.
One is to try to "patch" the ST's weaknesses against the Amiga which we know hurt it in gaming later in the 80's. We could try to add more colours, better graphics performance, better sound etc etc.
The other direction to go, which is better in my view, is to build on the ST's strengths over the Amiga (eg the strength it ended up having in music with the MIDI ports, or the raw computation power it had with the extra 0.5mhz, which made spreadsheets etc a bit quicker, and during the raytracing and fractal trends made the ST a little bit quicker to render images than the Amiga). You could focus on that, playing to it's strengths.