Vic96

6567 basically supported bitmapped or character mode, each of them either hires or multicolour, then overlayed 8 sprites. (ok, and also EBCM for 4 bg colours. Is this used for anything other than writers?)
vic96 is like 6567 only wider and more flexible.

Screen data:

• Colours are 15 bits wide, not 4.
• chars are now 16 bits wide not 8, and are a direct offset to a definition.
• Data fetches are as follows:

  char   = *(screenmap+rowmap[y]+x)
  attrib = *(attribmap+rowmap[y]+x)
  16cell = *(cset     +finemap[y] + char)
  

• cset,screenmap,attribmap,rowmap & finemap are all 16 bit pointers within vic96 These replace $d018 and y-scroll (low bits of $d011) The rowmap and finemap arrays are read at the start of each raster-line. the cset, screenmap and attribmap arrays are read once per 16cell
• Each 16cell contains eight 2-bit pixels or four 4-bit pixels.
• A 2 bit pixel LERPs between the background colour ($d020!) and the character colour, obtained from attrib.
• A 4 bit pixel does what? Want to use some global data and some local...
  Uses attrib to point to a 16 entry colour table? That gives the power of EBCM, and all the flexibility of MCM, and more :-)

Sprites:

{x,y,height,colour,definition:word; colourmode:bit}

Similar colour control as characters? gets you either anti-aliased hires or 4bpp with a vic register pointing to a colour table. zero is 100% transparent in both cases.

Can be retriggered, just like 6567.

How many? How wide?

One more than required to cover a raster line would be nice.. 16x32 pixels=512 pixels wide, but eats loads of bandwidth How big is the screen anyway?

• 320x200? 400x250? 512x320?
• small enough to emulate 100% on a 75Mhz 603 :-)

And what about borders?
Do we want to be able to build a real one and feed it into a tv?