Date   : Sun, 03 Sep 2006 14:08:04 +0100
From   : Sprow <info@...>
Subject: Re: CC Graphics ROM

In article <00b601c6cf3c$024d3700$0701a8c0@...>,
   Bob Devries <bdevries@...> wrote:
> Sprow said:

> > The CC graphics I have reports
> > Graphics Extension 2.09
> > The Acornsoft one
> > Acornsoft GXR 1.20
> > in response to *HELP. Does yours?
>
> No. There is no mention of a graphics ROM when I type the *HELP command.

It's probably disabled. This suggests it's the computer concepts one then
since the Acornsoft one responds even if turned off.

A quick nosey at the disassembly shows top bit of &3A4 is being used, so

 ?&3A4=?&3A4 AND127
 *HELP

will wake it up and

 *HELP GRAPHICS

lists the commands. Further inspection shows unknown OSBytes (service call
7) are filtered off before testing top bit of &3A4, and that a

 *FX162,<number> 

writes <number> to the flags@&3A4 amongst other things, presumably the
manual would detail the relevance of other bits in this location,
Sprow.