Re: A86: contrast


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Re: A86: contrast




I totally forgot about _vputmap.  In that case, one could just do this:

dispContrast:
	ld a, $c008	;retrieve contrast value
	add a, $30	;create ASCII character value
	call _vputmap	;display ASCII char in register A
	ret

Cassady Roop


Diego Pontoriero wrote:
> 
> Ok this is my thoughts on this (I've already read like 7 emails on it).
> 
> The problem you're having with outputting is that, as other people
> mentioned, _vputs writes text on the screen based on the values at (hl),
> increasing until it sees a zero.  Now, theoretically to output the contents
> of a register, the only ROM routine for a variable-width is call _vputmap.
> It outputs a at the _oenCol and _penRow locations.  However, the data stored
> at $C008 isn't in ASCII, so even if you tried a call _vputmap you'd still
> get trash.  So here is a routine chicane uses.
> 
> DispHL:
>         ld de,-1
>         ld (_curRow),de
>         call _dispahl
>         dec hl
>         call _vputs
>         ret
......


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