Re: A86: Graphics

To: assembly-86@lists.ticalc.org
Subject: Re: A86: Graphics
From: Robby Gutmann <gutmann@planet-connect.com>
Date: Wed, 22 Oct 1997 20:49:58 -0500
Reply-To: assembly-86@lists.ticalc.org

>Ok, you can either use the ROM calls (takes longer, but is a little easier),
>or you can write directly to the video mem.  I'm not sure what registers the
>_ILine, _IPoint, and _CLine calls use, but there's some documentation on that
>somewhere (If not on the 86, then on the 83, just change all the 96's that
>refer to the xmax to 128's)


ok, i figured those out, thanx very much.

>For writing directly to video mem (1024 bytes, starting at $FC00, unless you
>move it - each byte is 8 pixels)

ok, i read a description of the 86 ports, and i figured out some rudimentary
stuff.

>, you need (usually) a findpixel routine,
>which you can find earlier on this list, or probably in ticalc.org's source
>archive.  Basically, tho, you might try something like this:
>
>ld d,<y_coord>
>ld e,<x_coord>   ;i think this is right
>call FindPixel     ;points hl to pixel, with mask in a.
>or (hl)                 ;is this a valid opcode?  if not, improvise...
>ld (hl),a              ;put it back in (hl)
>
>If you already know the (x,y), you might just want to do something like this:
>
>ld hl, $FC00+16*y+[x DIV 8]
>set 7-[x MOD 8],(hl)
>
>You probably should precalculate the #'s, tho...

now, this is where you lost me.  i have no idea what you are talking about.
could you explain this me, slowly, carefully, as if i have absolutely no
clue what any of those terms mean (which is pretty close to true)?  id
really appreciate it.  thanx

Robby Gutmann
gutmann@planet-connect.com
ICQ UIN: 724927      Agonostis on IRC

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