[A83] Re: Grey scale(and enterlacing, is that the right word for it?)


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[A83] Re: Grey scale(and enterlacing, is that the right word for it?)




On Sun, 30 Dec 2001 Mike3465@aol.com wrote:

>
> Ok, I have a small problem which is odd.
> I have it set up so it should display a completly grey screen.
> but it has garbled junk on it, this is what i'm using right now:
>
>     ld bc,768
>     ld hl,SafeRam1
> loop1:
>     ld (hl),255
>     inc hl
>     djnz loop1
>
>     ld bc,768
>     ld hl,gbuf
> loop2:
>     ld (hl),0
>     inc hl
>     djnz loop2
>
> anyone know whats wrong?

Djnz only uses B and you use BC. Try the following.

	ld	hl,SafeRam1
	ld	de,SafeRam1+1
	ld	bc,767
	ld	(hl),0
	ldir

> oh, and the grey scale looks fine, but it's only 3
> level, what was the guy talking about 4 level?

You could make 3 routines exactly as your first routine now. Instead of
%10101010 and %01010101, you should use

%11011011 and %00100100 in the first routine,
%10110110 and %01001001 in the second routine and
%01101101 and %10010010 in the third routine.






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