Re: A85: Conversion from 82

To: assembly-85@lists.ticalc.org
Subject: Re: A85: Conversion from 82
From: mgp4007@omega.uta.edu (Michael Pearce)
Date: Sun, 18 Oct 1998 20:34:01 GMT
Delivered-To: assembly-85-outgoing@towerguard.unix.edu.sollentuna.se
In-Reply-To: <362A4802.9D1AB38D@freewwweb.com>
References: <362A4802.9D1AB38D@freewwweb.com>
Reply-To: assembly-85@lists.ticalc.org

don't most ti82 games use a call DISP_GRAPH (or something like that).
it copies from the GRAPH_MEM to the display.  you could just write
your own DISP_GRAPH routine which could map the 82 screen to the 85
(i.e copy 96 pixels for each row like on the 82 instead of 128 like on
the 85).  maybe something like this (have no idea how correct this
is):

DISP_GRAPH:
 ld a,64		; 64 rows of video on both 85 and 82
 ld b,0			; b is always 0
 ld hl,GRAPH_MEM	; copy from GRAPH_MEM
 ld de,VIDEO_MEM	; copy to VIDEO_MEM
D_Gloop:
 ld c,12		; bc = 12 bytes of video/row on 82
 ldir			; copy 1 row to the VIDEO_MEM
 inc de \ inc de	; \ 16 bytes of video on 85 so
 inc de \ inc de	; /  move to next row of video
 dec a			; one less row to copy
 jr nz,D_Gloop
 ret

-mike pearce

On Sun, 18 Oct 1998 15:56:51 -0400, you wrote:

>
>Does anyone know the easiest way to convert from an 82 to 85 display?
>
>

References:

A85: Conversion from 82

From: Mike Koss <mikekoss@freewwweb.com>