Date   : Mon, 25 Mar 1996 14:52:45 +0000 (GMT)
From   : Roger Walker <Roger.Walker@...>
Subject: Re: My emulator -- small problems

On Mon, 18 Mar 1996, James Fidell wrote:
> Tom Seddon wrote:
> 
> > 1. The BREAK key
> > 
> > Sometimes this doesn't work. The screen clears and there are a couple of
> > blobs, but you have to press BREAK to start again. Does the Break
key work
> > OK all the time in Xbeeb/MacBeebEm? (I've never used these two) To their
> > respective authors: how do you handle the break key? I just do a
> > SEI:JMP(&FFFC), without resetting the hardware (since the reset routine
> > will do this for me). Is this wrong? 
> 
> I do a power-up reset on most of the hardware, too.  It may not be
> right, but it seems to work for me at the moment.
> 
> James.

The circuit diagram shows the BREAK key connected to the reset line, so most
chips (those connected to the reset line), will treat it exactly the same as
a power up reset.  The soft reset/ctrl reset options are selected by
(I think)
checking the system VIA which powers up to one set of defaults but reset
doesn't doesn't change.  Also certain memory locations are checked for the
*fx200,3 value and for the jump on reset values (is it 427,428,429h ?) used
by a few games.

Roger Walker.