Re: A83: invert part of screen

To: <assembly-83@lists.ticalc.org>
Subject: Re: A83: invert part of screen
From: "Harper Maddox" <gte172i@prism.gatech.edu>
Date: Sun, 23 Jan 2000 21:10:34 -0500
References: <00b201bf65fa$6e189f40$2f4deed4@schulpen>
Reply-To: assembly-83@lists.ticalc.org


there is a much easier way...

it will run alot faster if you dont use sprite routines, since you know this
is all aligned.  If you want a different style routine that does not affect
the graph buffer you should check out the source for the cursor in Sqxrz 83.


; inverts the next 8 rows starting at de
;  so to figure out the starting pixel use the following formula "ld
de,plotsscreen+12*ROWS"

invert8pixels:
 ld b,96            ; 8 rows * 12 bytes per row
invert8pixLoop:
 ld a,(de)
 cpl                ; a = the complement of a
 ld (de),a
 inc de
 djnz invert8pixLoop

 ret

References:

Re: A83: invert part of screen

From: "Daan {DreAdFaq} Schulpen" <DreAdFaq@gamestats.com>

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