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What is the screen resolution of an Amiga Game NDOs ?
i know workbench can have different screen resolutions, i guess games under workbench can also have some different resolutions, but what i am asking is the traditional NDOS games,
what resolution they use? OCS and AGA? are there may games done for ECS?
Games use the standard PAL or NTSC (depending) resolutions.
OCS/ECS/AGA PAL
320 x 256 (low-res)
320 x 512 (low-res interlaced)
640 x 256 (hi-res)
640 x 512 (hi-res interlace)
704 x 576 (overscan)
Colors are from 2 up to 4096 using HAM mode. There's also the EHB (Extra Half Brite) mode which has 64 colors (actually it's 32 colors but their colored pixels are halved). That's for OCS/ECS.
Normally games had 32 colors in low-res mode which is the maximum, and 16 colors in hi-res mode which is the maximum too. That's for OCS/ECS.
The same applies to AGA which introduces 256 colors instead of 32 colors, as well as HAM8 mode which can have up to 16,7 million colors.
To sum it up, almost all games under OCS/ECS mode use low-res resolution with 32 colors (very few with 64), and very few also in hi-res mode.
On the other hand, games under AGA mode use low-res resolution with 256 colors instead.
Thanks Phantom, great info.
Great summary Phantom. :)
Some small additions regarding colour.
With OCS/ECS the HAM mode utilises and can display the total available system palette of 4096 colours on screen at once. With AGA HAM8 it can display 262K colours from a palette of 16.7 Million colours, so not the complete palette at once, but even so, 262K colours is more than enough for most images.
Thanks for the correction Dave. :)
Interestingly, I also read that HAM8 might not actually be restricted to 262K colours. This is based on resolution and other factors. In fact, some have reported that using an Indivision flicker fixer and its own screen modes it should be possible to display over 800K colours on screen at once. Most interesting.
There is also something called SHAM, SuperHAM or more technically known as SplitHAM. This was developed by the Demoscene for OCS/ECS machines and uses the copper to renew the palette ever scanline of the screen redraw in HAM6 mode, allowing a complete palette switch for each line of the screen, in theory allowing full 4096 colour modes in higher screen resolutions than HAM6 is normally restricted to.
HAM8 mode should be over that colour limit, as the Amiga can open new vertical display screens (and resolutions) on just the one physical screen. You can see this in action if you load multiple copies of DPaint with ham8 images loaded, then drag one (or more) down to reveal the screens behind. They should all still look correct.
This applies to 32 colour and HalfBrite screens as well, so a game could open the main display port in 32/64, but have the score board with it's own colour palette.
Also, if you give up a colour from the palette, you can use the copper to create a colour gradient independent of the main palette.
This is probably why screengrabbing Amiga games can give you such a varied number of colours -even in the same game!
So very true. The Amiga was far more advanced of any other system at the time. With other systems like the Atari ST, the 16 colour screenmodes basically meant that was all you had to play with, but with the Amiga's custom chip set, using the copper and blitter you could perform all kinds of tricks to the display, even changing the colour palette on the fly between each scanline of the display as it was drawn, so saying an Amiga game screen is normally 32 colours isn't telling the whole story at all and is really just the starting point for the programmers. Its probably more accurate to say they only had access to a 32 colour palette at any one moment.
Of course the other huge advantage the Amiga had over other systems was the custom chipset being independent of the CPU, so they could get on with processing the video and audio, directly accessing the chip ram, whilst the CPU could be left free to perform other duties and utilise any fast ram separately.
The Amiga is still as amazing a piece of computer engineering as it ever was.