A nice book to have and I can recommend it to people.
It will take me ages to read it all though as I like to read page by page from the start
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Moderator: BigEvilCorporation
Author is @keefstuart on Twitter, might be worth a poke about his sources and if he has more of the doc available.Nemesis wrote:Oh man, pity there aren't any more pages of that VDP manual visible, it'd be great to see the full official register list, might give us answers about the few VDP register settings we still don't understand.
We wanted the Mega Drive to have the basic performance of the preceding system boards — the System I, System II and System 16 — and we wanted to preserve compatibility with the Mark III. In fact, even SG-1000 II titles were playable on the Mega Drive. The top priority was the Mark III compatibility
The biggest hurdle was the size of the chip. We wanted to include enlarging and minimizing capabilities as well as sprite-spinning functionality, but the circuit design was becoming too large to fit on one chip, which would have lowered the production yield rate and hiked up costs, so we had to remove it from the spec. The number of available colors was also limited by the size of the circuit structure.
Interesting how interlaced mode seemed so much important to him, yet it was only used in 2 or 3 games. I guess most people now would have prefered improved color RAM over this featureThe complex circuit designs were FIFO memory, read/write of one line buffer method for drawing, and interlace display.