Missing Display modes

[Cyprian]

I would say bitplanes were chosen due to limited memory bandwidth vs a screen size at that time.
In case of bitplanes, to set 16 pixels we need write only one word. In case of 8bit chunky mode - eight words.

[dmacon]

Things I am missing from AGA, which realistically could have been done in 1990/91:

- 16 color, 8 sprite mode (32x32, 16x16), instead of ridiculously large 64x64 4 color sprites
- Flexible DPF modes. 5 BP / 3 BP would have been REALLY useful.
- Using the UHRES feature + VRAM to implement 4,8,16-bit packed pixel modes (aka „chunky“), which form an extra plane to be imposed over bitplane display
- Copper move multiple with autoincrementing destination address to speed-up palette loads
- Support blitting of interleaved planes with a single bit plane mask
- Copper interrupt function & extra JMP / LINK register, wired to blitter end IRQ
(…)

[dmacon]

Originally Posted by Cyprian

I would say bitplanes were chosen due to limited memory bandwidth vs a screen size at that time.
In case of bitplanes, to set 16 pixels we need write only one word. In case of 8bit chunky mode - eight words.

Contrary to popular opinion, I think the way how bitplanes are supported in the Amiga gave the system a BIG advantage in flexibility and speed over any other platform from that era. Lots of colourful 2D effects are possible with that implementation, which bring any 386 / early 486 VGA system to its pitiful knees.

Bitplanes ARE what the Amiga stands for, and would have been extended even further for AAA.

[Cyprian]

Originally Posted by dmacon

Contrary to popular opinion, I think the way how bitplanes are supported in the Amiga gave the system a BIG advantage in flexibility and speed over any other platform from that era. Lots of colourful 2D effects are possible with that implementation, which bring any 386 / early 486 VGA system to its pitiful knees.

Bitplanes ARE what the Amiga stands for, and would have been extended even further for AAA.

actually VGA (EGA and CGA too) next to chunky has also bitplane modes, where each of them can be independently "moved" in its ram, also there is interesting mode where with one 'move' instruction you can write to all bitplanes at once. It can saves a lot of cpu cycles.