chunky pixel mode

[Cammy]

If Amiga had a chunky mode, this would be even faster!

[YOUTUBE]RKixK1gxOns[/YOUTUBE]

Unfortunately it's only AGA.

[itix]

For a certain type of games sure. We'd all have loved to have UFO Enemy Unknown be less pokey. But there were plenty of areas where CPU power was important: Coding, all sorts of applications (including graphics which was a popular use of the amiga community), and later games.

It'd also permit more advanced games. Look at things like Genetic Species and Onescapee for some simple things that were possible with a decent 030 and AGA.

Better CPU allows better 3D games, better productivity apps and so on but PC world was already having SVGA as a standard and games used it.

After all in mid 90s Amiga was losing its fight on all fronts: 68k CPU arch was dying, AGA couldnt compete against SVGA, the OS development was slow and 4 channel 8-bit audio (Paula) was aging. Even if Commodore did few more things right they didnt have a chance.

And of course all those fancy companies making fancy games for PC...

[runequester]

This is true, but those were solvable problems ultimately. RTG, AHI and PCI sound cards, PowerPC stuff. They just weren't solved at the time it needed to happen.

[Crumb]

I suppose they could have done what Sony did with PS3, essentially put all the custom chips of the previous generation inside the new machine AND add the new more advanced incompatible custom chips.

IIRC project "Hombre" included amongst other goodies ECS Amiga compatibility in a chip (that's the reason cbm didn't want to release AGA information).

[psxphill]

Textured 3D was coming whether you liked it or not and 3DO/Saturn/Playstation all instantly aged the Jaguar/SNES/Megadrive over night. The 486 PC + byte per pixel VGA screen mode also did the same to the Atari and Commodore computers.

A chunky pixel mode on it's own wouldn't have made a huge difference, it would have needed a texture mapper added to the blitter as well.
 
If they could have achieved that around the a500+ timeframe then it could have saved them. The amiga had already started winding down by then and needed a shot in the arm. ECS was not good enough to keep people buying amigas. They could probably have stuck with a 68000 and still had some good games.

[ElPolloDiabl]

A lot of people say that Amiga was dead at the time of A500+
People wouldn't buy one when it was starting to lose popularity. Me as a user was was still happy till the A1200 release, which was a disappointment. Cool, but if the add-ons had been cheaper I would still have it as a second machine. Now it is just a retro machine, used occasionally.

[bloodline]

Just thinking about the possibilities... If Lisa had been given a 256 colour chunky pixel mode at 320 x 256, plus if she had 128k of ram as the chunky display buffer mapped to the chipset address space by where she had priority, and if the regular planar display could be mixed over the chunky display... We might have had something really cool to play with at relatively little extra cost...

[Mrs Beanbag]

if multiple displays could simply be combined together like layers in photoshop, a truecolour display could be made by adding three 8-bit paletted screens together!  (Chunky or otherwise.)  Plus any other weird and wonderful combinations one could dream up...

[psxphill]

Just thinking about the possibilities... If Lisa had been given a 256 colour chunky pixel mode at 320 x 256, plus if she had 128k of ram as the chunky display buffer mapped to the chipset address space by where she had priority, and if the regular planar display could be mixed over the chunky display... We might have had something really cool to play with at relatively little extra cost...

That sounds very complex to shoehorn in. Lisa already ran out of registers and you're going to have to duplicate alot of them for the dual chunky and bitplane mode.
 
I'd prefer the option of 640x512 chunky modes than being able to mix them.

[runequester]

Would the Amiga have been able to function with as little RAM as it had, using Chunky modes, or is that not an issue?

[Vanilla]

@lassie

Hi i have been thinking about 3D on Amiga and read about something called chunky pixel mode, if they had used that in an Amiga 1200 and CD32 would it have made the Amiga better at 3D games? or should there more to it, maybe more ram etc?

AlienBreed 3d had a copper chunky mode for the display mode. Which probably just modified a background colour or something with a 12-bit RGB pixel value. Most likely a manual CLUT mode was used with a lookup table to help. Or it was was used directly but then the instructios skipped over. It was at super low res. 160x256.

The CD32 had chunkly to planar hardware. You wrote some chunky in and read some planar out so it was still manually controilled to an extent.

[Vanilla]

@Crumb

More sprites would have made a real difference. Check out Neo Geo games. These are 2D only but impressive anyway. C

The Amiga had virtual spriites. Which could multiple them up to 64 IIRC provided the scan line had enough to work with. The OS even supported them. So you could program the OS instead of trying to work it out yourself.

[Mrs Beanbag]

You could fit a 640x512 truecolour (24 bit) screen in just under 1Mb.  I'd recommend a bit of FAST RAM as well, though.

Put simply, a chunky mode wouldn't use any more RAM than the equivalent planar mode.  Planar modes only save memory if you're not using all 8 bitplanes, except HAM8, which is clever but not much use for games (and in theory you could have a Chunky mode HAM anyway).

[Mrs Beanbag]

The Amiga had virtual spriites. Which could multiple them up to 64 IIRC provided the scan line had enough to work with. The OS even supported them. So you could program the OS instead of trying to work it out yourself.

But there are many complex and difficult limitations for virtual sprites.  Essentially you re-use the same sprites several times by using the copper, so there is no limitation on the number on screen but if you want them to be able to overlap arbitrarily you've got problems.  This trick has been used to get extra layers of parallax.

Also you lose a sprite when you start the screen data fetch early which is required for full screen hardware scrolling.  Note the Turrican game screen is actually 16 pixels in from the left!  Presumably this is so they can use all 8 sprites.

[runequester]

You could fit a 640x512 truecolour (24 bit) screen in just under 1Mb.  I'd recommend a bit of FAST RAM as well, though.

Put simply, a chunky mode wouldn't use any more RAM than the equivalent planar mode.  Planar modes only save memory if you're not using all 8 bitplanes, except HAM8, which is clever but not much use for games (and in theory you could have a Chunky mode HAM anyway).

Thanks for the clarification. So by the time we're talking 256 colours, there's no savings involved in planar?

[Zac67]

Which could multiple them up to 64 IIRC provided the scan line had enough to work with.

Actually, the Amiga's sprites are channels which are limited to 8 sprites per scanline. So, theoretically you could use up to 512*8 = 2048 on PAL interlaced with no more than 8 overlapping on any scanline.