Re: Display issues with CarteBlanche VGA?

["RedskullDC" <redskulldc@oohay.moc.ua>]

Hi Steven, et al.

"Steven Hirsch" <snhirsch@gmail.com> wrote in message 
rcedncDP95lM_IXWnZ2dnUVZ_hCdnZ2d@giganews.com">news:rcedncDP95lM_IXWnZ2dnUVZ_hCdnZ2d@giganews.com...
> Occasionally I get artifacts on the display when using the CB as a VGA 
> adapter.  These generally consist of spurious characters, normal and 
> inverse.

Problem is in vga_video.v
Each scan line is displayed twice for VGA.
On the last scanline of the last character of the second scanline,
"vc" is being incremented before the RAM address being sent to the
SRAMS has been calculated.

Line #218 of vga_video.v
from: http://alexfreed.com/FPGApple/CB/CarteBlanche_500/vga_video.v

(I have the 500 version of the card by the way.)

Change
wire next_vc = clk1  &&  allow_shift7 && (count7 == 6) && (hc == 63) && 
((aux_byte == 1) || ~mode_80COL);
to :
wire next_vc = clk1  &&  allow_shift7 && (count7 == 0) && (hc == 63) && 
((aux_byte == 1) || ~mode_80COL);

Tested this end, seems to fix the problem ok.

> Also, "MouseText" characters always seem to display as ASCII instead of 
> symbols and line corners.

Haven't played with MouseText as yet.

Any chance you could post some pics showing the problems?

> Are any other CB users seeing this?
>
> Steve

Cheers,
Red