VERA 0.9 640x480x8 - not enough memory

[SerErris]

VERA 0.9 has defined that it can run in 640x480 in bitmap mode with 8bpp ... but that would to my calculation require 300kb and we only have 128kb video ram (even a little less if you remove the register space).

Am I overlooking something or does it no longer support 640x480 at full 8bpp bitmap mode? 320x240 should fit with 256 colors ... 

So is it intended that we can use 8bpp only with scaling factor of 2?

Cheers

Ser

 

 

[SlithyMatt]

That's correct, even though a setting is possible, it's not necessarily useful. Trying to do SVGA on the X16 will result in a bunch of garbage at the bottom. Now, you can do 80-column text mode with 256 colors, or 16x16 tiles with letterboxes to get the same pixel size. In general, graphics work best in 320x240 mode.

[SerErris]

Thanks for confirmation ... So I need to write my graphics mode fractral in 320x240 with 8bpp ... lets see how fast this will be ... ?

I do in basic first and then try a assembler version.

[BruceMcF]

When this came up on Facebook it was demonstrated that It can be used for some special effects, like a scene in the top of the screen reflected with a water effect beneath, which is just redirecting Vera to the same graphic information with different settings as it works down the display.



You could also have a "viewport" into high resolution graphics in the lower layer where the upper layer obscures that there's not much in that lower layer except what is showing through the "viewport".

[SerErris]

Yep, somthing like an Ultima IV thing. The graphics was tile based anyhow, but it was a very small part of the screen actually showing the graphics.

That makes perfectly sense. You could have a 16 color text layer and a 256 color 8bpp bitmap mode on the other layer  as a window or such. Very good.