English Amiga Board - Copper timing

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- - Copper timing (https://eab.abime.net/showthread.php?t=38014)

Quote:

Originally Posted by chb (Post 1308583)

That's probably true, but I'm still wondering why they did not include a cheap-and-dirty 16 bit mode - just pass the data to the external RAMDAC, no CLUT involved. If you want it really super simple you could even omit horizontal scrolling and hardware sprites. Would have resulted in a 65k color mode that uses 50% of chip mem bandwidth in lores, with a very convenient chunky format.

This is my thinking, you don’t need any of the fancy stuff Denise/Lisa does with a chunky mode, we already have the 16bit beam synchronised fetch... it just need to feed the DAC (which is also already prensent in the A1200) directly!

Quote:

Originally Posted by bloodline (Post 1308306)

Ahhh, yeah... AGA’s blitter is the same as the original chipset :crying Also it seems mad that once Commodore were using RAM chips which had the bandwidth to do 8bits per pixel, they didn’t include a chunky mode (I mean what engineer would not think of that?!

Even OCS already had enough DMA bandwidth to fetch 8 bits per pixel (640 x 4bits = 320 x 8bits).

If the OCS chipset had had 256 color registers we would have had a chunky mode for very little cost, although obviously it would be quite slow to animate given the almost complete DMA saturation this would imply.