Agnus and Denise Rebuild

[trekiej]

If Agnus and Denise were remade to be chunky instead of planar, what other conversions would have to be made?

The first thing comes to mind is the exec.  Would it have to be made compatable or would the chip have the same appearance as the original chip?

Just rambling.  :-D

[bloodline]

trekiej wrote:
If Agnus and Denise were remade to be chunky instead of planar, what other conversions would have to be made?

The first thing comes to mind is the exec.  Would it have to be made compatable or would the chip have the same appearance as the original chip?

Just rambling.  :-D

Why is a mouse when it spins?

-Edit- Ok a real answer... Denise is responsible for display generation and thus is the Planar component... Changing her to chunky... all software would break.

[trekiej]

@ bloodline:
I guess I am currios how that is seen by the system.
Would that include a change in *.device?

[bloodline]

trekiej wrote:
@ bloodline:
I guess I am currios how that is seen by the system.
Would that include a change in *.device?

All that would happen is that pixels would be arranged differently in memory, you wouldn't be able to do certain effects like dual playfield without the Blitter and all gfx would be corrupted for software which assumed Denise was still working the old way.

[trekiej]

@ bloodline:
Sounds like banging the hardware would be a big problem too.
I just trying to feed my new amiga adiction. :-D

I guess the Akiko ( I believe that is the name )chip in the CD32 had the right idea.

[AeroMan]

trekiej wrote:

I guess the Akiko ( I believe that is the name )chip in the CD32 had the right idea.

The way Akiko was done was a nice approach, as with it you could use the available chips and OS, but my prefered solution would be create some extra modes, and keep the old ones.
Commodore could have done a "chunky chip", instead of Akiko, to receive the DMA data from Alice/Agnus and display it if the chunky modes were selected. Data output could be switched to feed one chip or the other one.
I bet they had a good reason to go with Akiko, but I like to think how different it could have been :-)

[Zac67]

In hardware, only Denise would have to be changed. In software all graphics related stuff would need to be rewritten (graphics.library, intuition.library?, application code banging the hardware). This is also necessary for RTG cards (most use chunky modes, too). The only way to go compatible is to add chunky modes and keep the planar ones. (IMHO missing this opportunity on the AGA chipset was a big mistake; software support could've been added later.)

OTOH, adding an RTG card takes care of the same problem, usually adds a lot of 'chip' RAM and allows for faster processing. So if you're not talking about recreating the Amiga and adding chunky modes en passant (e.g. Minimig), the RTG path would be the smarter one.

[Egg-Chen]

The Falcon030 seems to have both Planar and chunky because the Gfx chip allow the use of 256 colors on screen out of a 262144 colors palette,  or 65535 colors out of 65535 colors palette (without color limitations like the HAM mode) in its 2 distinct video modes.  

Maybe the Amiga designers should have gone this way when designing the AGA chipset, the Falcon030 proves it was not impossible, and the Gfx chip also remains compatible with the old ST video modes too...

[shoggoth]

Egg-Chen wrote:
The Falcon030 seems to have both Planar and chunky because the Gfx chip allow the use of 256 colors on screen out of a 262144 colors palette,  or 65535 colors out of 65535 colors palette (without color limitations like the HAM mode) in its 2 distinct video modes.  

The hicolor mode is chunky, but the other modes are not. An 8-bit chunky mode would have made quite a difference, since it's much easier to manipulate than a hicolor mode.

Maybe the Amiga designers should have gone this way when designing the AGA chipset, the Falcon030 proves it was not impossible, and the Gfx chip also remains compatible with the old ST video modes too...

It's far from impossible, but as someone pointed out, you'll have to write new drivers for the system. Compatibility with old apps is no problem as long as you keep the possibility of using legacy resolutions. There is a hardware project for the CT60 (060 expansion for the falcon) which intends to do this. Basically it aims to be register compatible with the original VIDEL chip, but adds 24-32 bit truecolor capabilities as well as 8 bit chunky modes.

[shoggoth]

AeroMan wrote:
I bet they had a good reason to go with Akiko, but I like to think how different it could have been :-)

One guess could be that it's a very cheap solution. If I understand it correctly, it's basically a FIFO thing - you write 8 longwords of chunky data, which when read back becomes 8 longwords of planar data. No changes of the original chipset was required. Naturally, a "real" chunky mode would have been more efficien, but all and all it's not a bad solution considering the circumstances.

[Speelgoedmannetje]

Egg-Chen wrote:
The Falcon030 seems to have both Planar and chunky because the Gfx chip allow the use of 256 colors on screen out of a 262144 colors palette,  or 65535 colors out of 65535 colors palette (without color limitations like the HAM mode) in its 2 distinct video modes.  

Maybe the Amiga designers should have gone this way when designing the AGA chipset, the Falcon030 proves it was not impossible, and the Gfx chip also remains compatible with the old ST video modes too...

AFAIK the Falcon030 WAS designed by (ex) Amiga designers. :-)

[bloodline]

Speelgoedmannetje wrote:

Egg-Chen wrote:
The Falcon030 seems to have both Planar and chunky because the Gfx chip allow the use of 256 colors on screen out of a 262144 colors palette,  or 65535 colors out of 65535 colors palette (without color limitations like the HAM mode) in its 2 distinct video modes.  

Maybe the Amiga designers should have gone this way when designing the AGA chipset, the Falcon030 proves it was not impossible, and the Gfx chip also remains compatible with the old ST video modes too...

AFAIK the Falcon030 WAS designed by (ex) Amiga designers. :-)

It wasn't, but the falcon was what the A1200 should have been.

[shoggoth]

Speelgoedmannetje wrote:
AFAIK the Falcon030 WAS designed by (ex) Amiga designers. :-)

Er... no.

[biggun]

trekiej wrote:
If Agnus and Denise were remade to be chunky instead of planar, what other conversions would have to be made?
 

An Amiga chipset which is compatible with Planar/Chunky & Truecolor formats?
Sounds like this Amiga:
http://www.natami.net/specification.htm

[amigadave]

biggun wrote:

trekiej wrote:
If Agnus and Denise were remade to be chunky instead of planar, what other conversions would have to be made?
 

An Amiga chipset which is compatible with Planar/Chunky & Truecolor formats?
Sounds like this Amiga:
http://www.natami.net/specification.htm

EXACTLY!

I would love to see the whole Amiga community get behind the Natami project and other projects like it that will likely be created in the near future.