[Coco] help with drawing

[jdaggett at gate.net]

Easier

Get the Super Extended Basic Unraveled  II Series and trip lightly 
through the disassembled code to see where the routines are.

Modt Hxxxxx Code is above $E600

james


On 18 Feb 2005 at 23:37, Andrew wrote:

Date sent:      	Fri, 18 Feb 2005 23:37:54 -0700
From:           	Andrew <keeper63 at cox.net>
To:             	coco at maltedmedia.com
Subject:        	[Coco] help with drawing
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> Get a the CoCo 3 SUPER EXTENDED BASIC ROM dump, and find where all the
> routines are for the screen commands (HSCREEN, HSET, HGET, HPUT, etc)
> - then look and see if/where/how they reference the standard location
> for the regular HSCREEN (2, in this case) - how it is set up. I would
> imagine there is some kind of table, and register(s) are loaded by a
> lookup into that table - which affects all of the commands. Then, all
> you need to do is figure out a way to change that table or register
> via a POKE (or LPOKE) to an offscreen area (should be room on a 128K
> CoCo 3), then draw your stuff, then HGET it, then change the register
> back, then HPUT it...