Date   : Fri, 04 Nov 2005 10:17:39 +0000
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: BBC B + 128

"John" <blip@...> wrote:
> Now that I think about it, SRAM 1.02 might be missing from the ROM listing
> under *help
> 
> The existing DFS (removed) did have a label saying 'modified B+ DFS' if that
 
The DFS has code to implement service call &2B which tells the MOS
how much sideways RAM there is. Without that the MOS will claim
there is only 64K - 32K or main RAM, 32K of shadow screen RAM. See
the earlier thread about the string "48K 64K 80K 96K 112K 128K"
appearing in the DFS ROM.
 
Also, without the DFS you will have no SRam commands built-in. You
will need the in another ROM or run them from disk. See
http://mdfs.net/Mirror/Archive/JGH/Utility2.zip which contains
disk-based SR commands - *SRLoad, *SRSave, *ROMS.
 
The sideways RAM will still be there, it's just the MOS doesn't
know about it, so can't announce it on startup.
 
> Do ROMs like the ADFS 'clash' with existing management ROMs like some kit
> does with a PC?
 
They shouldn't do, though there are some DFS extension ROMs that
implment commands such as *FREE which they claim before ADFS
claims it. It then tries to do a DFS *FREE on an ADFS disk.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
There are three food groups: brown, green and ice cream.