[atari7800] Re: DMA TIMING

Eric wrote:

>I just had an AH-HH! moment about this.  MARIA has two 800 bit line RAMs, so
>each 160H pixel has 5 bits as a color LUT index.  The 320H modes don't
>change how the line RAM is written to, just how it is read.  Which,
>unfortunately, means there are only 2.5 bits per 320H pixel, or max 8 colors
>per pixel with one bit shared between the two half pixels.

Any way to get that extra colour back? Since we're limited to 6 colours and 
2xbackground in 320B....

Actually, doesn't 320C use 8 colours + background? Except neighbouring bits 
must share the same colour. Well, can't have everything, can you...

Actually if you switched between 320B and 320C you'd have 12 colours + 
background on screen (without twiddling registers during interrupts). Could be 
a hideously complex DL/DLL and might be tough to juggle (maybe with 2 
two-scanline vertical resolution for movement so you can alternate 320B/320C?)

Hmmm....

Chris...

Other related posts: