Re: A86: Line routines

To: assembly-86@lists.ticalc.org
Subject: Re: A86: Line routines
From: PXGray@aol.com
Date: Sun, 2 May 1999 15:00:22 EDT
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: assembly-86@lists.ticalc.org
Reply-To: assembly-86@lists.ticalc.org


In a message dated 5/2/99 9:14:16 AM US Eastern Standard Time, 
rabidcow@juno.com writes:

> are the lines in a fixed location or do they move or have to be
>  calculated?
>  
>  if they're gonna be fixed, you can do something like:
>  	ld hl,$fc44		;start location ($fc00 + 16*y + x/8)
>  	ld de,16		;bytes to next line
>  	ld b,21-1		;height of line (h-1)
>  vloop: set 6,(hl)		;pixel within byte (x%8)
>  	add hl,de
>  	djnz vloop
>  	set 6,(hl)		;pixel within byte
>  to draw a vertical line
>  
>  also, do the horizontal lines start/end on a byte boundry?
>  
>  starting on a byte boundry:
>  	ld a,$ff		;8 pixels on
>  	ld hl,$fc45		;starting location 
>  	ld b,7-1		;width-1
>  hloop:	ld (hl),a
>  	inc hl
>  	djnz hloop
>  	ld (hl),a
>  
>  -josh
>  

The lines will not move at all, and I have no idea what you mean by a byte 
boundary.  Can you comment this, so I know what I am looking at?  Thanks.

.db "Patrick Gray",0