A86: Video RAM problem

To: assembly-86@lists.ticalc.org
Subject: A86: Video RAM problem
From: KidFedX@aol.com
Date: Mon, 23 Nov 1998 19:58:59 EST
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-86@lists.ticalc.org


okay, I have a problem with the video RAM; in my program (the intro) I turn
all the pixels on (for a night sky) and then I want to put some stars in.  I
want these stars in specific locations so I decided to load the bits into
locations manu.  but when I loaded say %11101111 into $FC33; $FC34 instead of
being %11111111 would turn to %00000000.  Why is it doing this?  I have a
black screen with dots in the right places, but one address location over it's
all blank.  Oh, and if you know an easier way to do this, could you tell me
please?  Thanks a bunch!

Here's the section of code:

#include "ti86asm.inc"

.org _asm_exec_ram

  call _runindicoff

BLACK:
  ld hl,$fc00
 ld d,h
 ld e,$01
 ld bc,$03ff
 ld (hl),c
 ldir

LITTLESTARS:   ;this will put stars in black sky
  ld hl,%11011111
  ld ($FC3F),hl
  ld ($FCB9),hl
  ld ($FEB5),hl
  ld ($FF36),hl
  ld ($FFB9),hl
  ld hl,%01111111
  ld ($FD1D),hl
  ld ($FDA5),hl
It goes on in the same fashion.

Follow-Ups:

Re: A86: Video RAM problem

From: Josh Grams <j3grams@earthling.net>