--- In gbadev@egroups.com, "Web Dreamer" <rownik@h...> wrote:
> >1. How much Ram the GBA has (compared to the 32k the GBC has)?
>
> I believe it's down to 32K of work ram, and now 256K on cart...
strange as
> it sounds. There is also the video memory, registers, etc.

Alrighty. Are you guys sure the 256k is on the Cart? Or is it a
possibility that 32k is like a CPU cache or just High RAM and the
256k
is something more like SIMM's or DIMM's on your PC (but of course not
replaceable). It does sound silly to have the ram on the cart (mainly
because it would be expensive for production costs of the cart, if
every cart had to have 256k of ram on it for the GBA.).

> >2. How many Sprites the GBA can display (compared to the GBC 40)?
>
> 128 on screen at 64x64 size, and 128 PER SCANLINE at 8x8 size.

Nice. So would that also mean if I had 16 64x64 sprites (128 8x8's
wide total), I'd be at my 128 sprite limit (hehehe... oh boy. I
don't see how I've lived so long with the GB's 10 sprite limit. :)
:).)?

> >3. What sprite modes are available (i.e. 8x8, 8x16, 16x16, ...)?
>
> 16 different sizes from 8x8 to 64x64.

Very nice. Is the mode selectable via 4 bits in the sprites
attributes, or is it like the SNES with 1 bit in attributes and 2
registers that select the 2 sizes to use?

> >4. The Attributes Setup (i.e. what is in it, how many bytes each
> >sprite takes up)?
>
> 4 bytes, including flags for h and v size, mosaic, color mode,
> semi-transparent... etc etc etc

Is that 4 bytes for everything, or just the attributes? Where does
the Scaling and Rotating fit in (please say attributes :), that would
kick so much!)?

> >5. How tiles are stored in memory (i.e. like GBC, but with 4 planes
> >instead of 2)?
>
> um... brain just went blank.

Alright. GBC stores each line of tile data this

bits
0 1 0 1 0 1 0 1 <- row 1 of 2
0 0 1 1 0 0 1 1 <- row 2 of 2

these rows or "planes" are mergerd to produce the following color
values.

0 1 2 3 0 1 2 3

8 of these produce your standard 8x8 tile. Now the SNES did the same
thing, but with 4 rows or "planes". Does the GBA do this too (for
the
16 color mode)?

> >6. The number of "Backgrounds" or "layers" the GBA has (compared to
> >the background and window the GBC has, and anything fancy about
them)?
>
> um 4, IIRC. Each scrollable, 2 rotateable/scalable. OBJ's moveable
between
> layers.

Very Cool.

> >8. How the Palettes are set up (i.e. how you load them, is it like
> >the
> >GBC with 2 registers you work with)?
>
> Regular old palette ram. In flavors of 256 colors in 1 palette or
16
colors
> in 16 palettes... with, of course, color 0 being transparent on the
display,
> like GBC OBJ's.

Are there seperate palettes of 256 for Background and Sprites (like
the GBC)?

> >9. Anything else really cool (such as the priority bit of the
> >attributes on the GBC, If individual sprites can have an Alpha
> >Channel
> >applyed to them, If Sprites can be rotated or scalled, etc...)?
>
> Well, plenty of things... BG maps ranging in size from 128x128 to
1024x1024
> with wraparound, mosaic effects, alpha blending (not too sure how
well it
> works yet), hardware LCD fade control, windows... itsa gonna be a
really
> nice leetle plataform to geta you hands on...;-)

Sounds very cool. I can't wait to get my hands on a kit. Thanks for
all the info.

--
PoV