Date   : Sat, 19 Feb 2011 00:15:14 +0000
From   : rs423@... (Mick)
Subject: *UNPLUG on a BBC B

J.G.Harston wrote:
> Mick wrote:
>   
>> I've removed my 'Watford electronics shadow RAM' ROM from my model B as
>> I got fed up of it intercepting calls on CTRL-BREAK resulting in my
>> machine booting into Interword or Wordwise rather than Basic.
>>     
>
> Can't you configure it to not do that? I'll dig out my manual and see
> what it says.
>   
I wouldn't have thought so. Configuring is not really a B thing is it. 
I've tried a few things in desperation such as *CLAIMOFF and moving the 
ROM workspace with no joy.


>   
>> *ROMON  '&'x (insert???), *ROMOFF' &'x (unplug) and *XROMS to switch in,
>> out or list ROMs.
>> Can anyone recommend a utility ROM that will allow me to regain these 3
>> utilities on my B? Perhaps there's any easy poke to do the same??
>>     
>
> ?(&2A1+romnum)=0 disables access to a ROM until the next Break by
> removing it's entry in the ROM service table.
>   
That is very useful to know. I've just tried it with 'Toolkit' just long 
enough to do a *FREE on ADFS / IDE.  I should really meddle with the 
'Toolkit' ROM and remove or rename *FREE from it. OR more simply move it 
in relation to ADFS.



> Many ROMs implement a permanent disable bit in the ROM workspace
> pointer, so ?(&DF0+romnum)=&80 then Ctrl-Break will effectively
> unplug them.

That is useful too. I've made a note of this and will experiment further.





>  DNFS uses two disable bits, &80 for NFS and &40 for DFS.
>
> *ROMs is available on Utility Disk 2 at http://mdfs.net/Mirror/Archive/JGH
> and http://mdfs.net/Mirror/Image/JGH
>   
I downloaded that earlier. Thanks for the link. You have *so* many 
valuable utilities on your site, it is often hard to remember where they 
all are. That's not a complaint by the way. You don't happen to have a 
memory editor there too though do you? I've just had to plug the 'Shadow 
RAM' ROM back in to get the use of *RAMEDIT back. The editor allows me 
to delve into ROM memory which is essential. The WE ROM in all is very 
good, if only it would behave itself during a Ctrl-Break.


Cheers,

Mick.