for the lack of answers, i think it could be, because its an hard question to answer, without getting too technicall
i also saw it the other day, and thought maybe an other would answer it, but tonight when i saw no other had answer it.
then I thought that i would give it a try, even if my English knowledge are not the best
maybe i read one of your answer wrong, but the Sega was made in 1988, and the ST was first showed at a Exhibition in 1984 so the Atari was 4 years ahead of the Sega.
overall i think that the ST was a great machine, it was not made to be a gaming machine, but to compete with the Apple computer.
so it was not so important that it did not features all those co processor.
I also think that was the reason for the 72HZ high resolutions on the ST, to make it a good allaround computer.
I have ones read that the blitter was intended to be in from the first ST computer but it was delay or something(but i don't really know) but you can get ST with a socket for the blitter, that you could add one later.
also some said that they also had planed for a another sound chip, (again don't know is true).
in the end i think, it was more important to get it finish and out of the door, instead of waiting for something that was not so important, for what it was intended for.
but the reason why i did loved the ST back then and probably also now, is because its very simple to code on.
You did not have to learn a lot of the co processors like you had on the Amiga, it was very straight for.
me and one of my good friends both had MSX prior, and we both used to coded on the MSX.
i chose the ST and he chose the Amiga, but the Amiga was to complicate so he stop coding, and he first started again when we moved on to the PC.
but the ST also had some advanced over the Amiga. and today you can do stuff on the ST/STE that you are not able to do on the Amiga 500, 1000, 2000, due to its hardware limitations.
sorry no book here, but when i am coding i use "Atari ST internals" to look up stuff, and if you are thinking on, starting coding on the ST and if you run into some problem, just post you question, and we will try and help you out.
and last congratulations with your Atari, i hope it will bring some inside and joy to the Atari
Edited by fedepede04, Wed Apr 17, 2019 6:29 PM.