The last Graffiti GFX Box produced, now available for $35.

[Karlos]

Looks kinda fun for the old 1200D, but I have no idea what I'd do with it :-)

[Karlos]

@Red

So do you know if there are any standard devkits for it? I googled a bit and found some stuff by Jens on how to hit the hardware for it but I was hoping there might be some sort of basic link library or something that allows easy use from C.

I guess there must be...?

[Karlos]

@bloodline

Saw that, but as it's such a simple thing I imagined there'd be one already?

Only reinvent the wheel when you can make it rounder ;-)

[Karlos]

P96?

Without support for 640 wide modes wouldn't it be of limited use to intuition applications?

By the looks of the documentation I so far found I'm not sure it can happily coexist with the existing graphics.library routines (although I could be very wrong about this).

It struck me more as a bit of a hardware hack to get chunky modes for game/multimedia type stuff :-?

-edit-

I'm sure you'd enjoy making a gfx library for it

Yeah, I have to admit, you got me there :-D

[Karlos]

Robert17 wrote:
It can do 720 wide in AGA I think... Yes Please pretty please with a cherry on top, write a P96 Driver for Graffiti!

Robert

Can it?

If it can do 640x480 or a similar resolution on AGA then I stand corrected. Still, I'm not totally sure how well it gets on with graphics.library, but as a P96 driver (which patches the graphics.library to support the hardware anyway) things are different :-)

[Karlos]

From Jens' site

maximum resolution with AGA chipset: 768x576 at 256 colours out of 262144 (interlace)

Rock on :-D

In that case I am sure that it is possible to create some sort of 8-bit p96 driver (akin in some respects to CGX-AGA, only without the need for any C2P), although I'm still highly dubious about the way it works with the existing graphics.library...

-edit-

One problem you get is that to use the 640 wide mode, you need a 4-bitplane SHRES arrangement, which means that you no longer have a linear arrangement of pixels. Adjacent pixels literally rotate through each of the bitplanes, so pixel 0 is in bitplane 0, pixel 1 in bitplane 1 ... pixel 4 in bitplane 0 and so on.

This does take the fun out of it slightly :-(

[Karlos]

It's just the way the thing works, apparently.

Each bitplane stores a run of 8-bit pixels. If you use a single bitplane you get a 160 width screen, with linear access to the pixel data. If you want a 320 screen you use 2 bitplanes, alternate bytes on each plane. For a 640 screen, you end up with four bitplanes, alternating pixels on each plane.

All of these are using SHRES displays on AGA. I can actually see that a 160 wide screen composed of 8 bit pixels would appear as a 1280 wide bitplane since there are 8 bits to each pixel. No doubt in order to be displayable you need to use the other bitplanes to bump up the resolution since 1280 is the widest displayable width you can have.

At least that's how I understood it.